Exposure apparatus

ABSTRACT

Two independent fine adjustment stages are arranged on one coarse adjustment stage to simultaneously perform all of focus measurement and part of alignment measurement in parallel with an exposure operation. A method of transporting a wafer together with a chuck is adopted as a precondition. Alignment of a pattern on a wafer with a chuck is performed before the chuck is mounted on each fine adjustment stage.

FIELD OF THE INVENTION

The present invention relates to an exposure technique for use in alithography process in the manufacture of a semiconductor device.

BACKGROUND OF THE INVENTION

FIG. 2A shows a typical arrangement of a conventional exposureapparatus.

In FIG. 2A, reference numeral 1 denotes a reticle; 2, a reticle stagefor scanning the reticle 1; 3, a reticle stage guide of the reticlestage 2; 4, a projection system; 5, an alignment scope for measuringpattern positions; 6 and 7, focus detection systems (light-projectingand light-receiving units) of a focus measurement system for measuringthe position of a wafer upper surface; 8, a wafer; 9, a chuck forholding the wafer; 10, a fine adjustment stage which can finely drive inthe X, Y, Z, and θ (this represents rotation in a direction parallel tothe X-Y plane (i.e., rotation about the Z-axis) hereinafter) directionsand in the tilt (this represents a tilt with respect to the X-Y planehereinafter) direction; 11, a coarse adjustment stage which can drivethe fine adjustment stage 10 in the X and Y directions; and 12, a waferstage surface plate of the coarse adjustment stage 11.

In the conventional semiconductor exposure apparatus, the alignmentscope 5 arranged adjacent to and at a distance BL from the projectionsystem 4 measures the position of a pattern on the wafer 8. Then, thewafer 8 is fed by the coarse adjustment stage 11 to below the projectionsystem 4. The reticle 1 and wafer 8 undergo scan operation relative tothe projection system 4 at a velocity of the magnification ratio of theprojection system 4 such that a pattern on the reticle 1 is transferredonto a predetermined position on the wafer 8.

In the above-mentioned transfer, the focus measurement system measuresthe position of the upper surface of the wafer, and exposure operationis performed while the fine adjustment stage 10 performs sequentialalignment in the focus direction such that the position of the uppersurface of the wafer coincides with that of the image plane of theprojection system 4.

The conventional semiconductor exposure apparatus has the followingproblems.

(1) Increase in Throughput

The conventional semiconductor exposure apparatus needs to measure theposition of a pattern on the wafer 8 below the alignment scope 5 beforeexposure operation. This is one of the major factors which limits thethroughput of the apparatus.

(2) Enhancement of Ease in Increasing Measurement Precision of FocusDetection System

The conventional semiconductor exposure apparatus needs to arrange thefocus measurement system for the wafer below the projection system 4, asdescribed above. For this reason, it is becoming difficult in terms ofthe mounting space to, e.g., implement a multichannel detection systemor improve a detection optical system to increase the measurementprecision of the focus measurement system.

(3) Relaxation of Constraints on Design of Projection System

In designing the projection system 4, the above-mentioned focusmeasurement system is arranged below the projection system and, thus, alarge back focal distance is necessary. This imposes considerableconstraints on the design of the projection system 4. Along with arecent increase in the numerical aperture (NA) of the projection system4, this problem has become serious. The problem will become serious in amirror projection system of a future EUV exposure apparatus as well.

(4) Facilitation of Cleaning Below Projection System

Recently, contamination from a resist has been perceived as a problem.To prevent this, a jet of clean air is provided below the projectionsystem 4. However, the focus measurement system described above is alsoarranged below the projection system 4, and thus it is difficult to forma complete laminar flow of clean air.

(5) Facilitation of Chuck Cleaning

As future exposure apparatuses, semiconductor exposure apparatuses usingan F₂ excimer laser or EUV light are being developed. In thesesemiconductor exposure apparatuses, the atmosphere for exposure lightmust be purged with nitrogen or must be evacuated to a vacuum. Asemiconductor exposure apparatus used in such an environment needs toperiodically extract a wafer chuck to the outer air side for cleaning. Aconventional exposure apparatus, however, has no chuck transportfunction required for this operation.

To solve some problems of a conventional exposure apparatus, thefollowing two methods are proposed. Their outlines will be describedbelow.

(A) Place Two Coarse Adjustment Stages on same Surface Plate

FIG. 2B shows the arrangement of improved method 1 in a conventionalsemiconductor exposure apparatus. Reference numeral 20 denotes anexposure wafer; 21, an exposure chuck; 22, an exposure fine adjustmentstage; 23, an exposure coarse adjustment stage; 30, a measurement wafer;31, a measurement chuck; 32, a measurement fine adjustment stage; and33, a measurement coarse adjustment stage.

The semiconductor exposure apparatus according to improved method 1 hasthe two coarse adjustment stages, two fine adjustment stages, and thelike. Exposure operation and measurement operations (alignment and focusmeasurements) can simultaneously and independently be performed for thewafers on the fine adjustment stages at exposure and measurementpositions.

When predetermined processes end at the exposure and measurementpositions, the fine adjustment stages are separated from the coarseadjustment stages and are interchanged. The wafer having undergone ameasurement operation is moved to the exposure position for the exposureoperation. Reference marks (not shown) are formed on the edges of thewafer chucks and are measured at the measurement and exposure positions.With this operation, measurement results (alignment and focusmeasurement results) at the measurement position are accuratelyreflected in exposure, and accurate alignment and focus are implementedat the exposure position.

Method 1 has advantages and disadvantages as follows.

(Advantages)

Exposure and measurement operations can be performed in parallel. If thetime for the measurement operation is equal to or shorter than the timefor the exposure operation, the measurement operation does not cause adecrease in throughput. Since enough time can be spared for themeasurement operation, multipoint measurement or the like can beperformed, and an increase in precision can be expected. Additionally,since a projection system and an alignment/focus measurement system arespaced apart from each other, constraints on the design of theprojection system can be relaxed. Cleaning below the projection systemis also facilitated.

(Disadvantages)

Independent operation of the two fine adjustment stages and two coarseadjustment stages increases the size of the entire stage and thecomplexity of a mechanism which interchanges the two fine adjustmentstages. It is difficult to ensure a long-term reliability and performreplacement in a short time. Also, since the two stages operateindependently of each other on one surface plate, their reaction forcesmake it difficult to keep the precision of scan synchronization betweena reticle and wafers high at a high stage speed. Additionally, eachstage basically has only a wafer transport function and requiresconsiderable alterations to add the chuck unloading function describedabove.

Typical known examples of improved method 1 include PCT WO 98/28665,which is the publication of Japanese patent application number2000-505958.

This known example discloses use of a counter mass to reduce effects ofreaction forces generated by the independent operation of the twostages. Only one counter mass is used for the two stages, and it isdifficult to completely remove the effects of the reaction forces.

As an example similar to the method shown in FIG. 2B, there is availablethe method discussed in Japanese Patent Laid-Open No. 10-163098.

As in the above-mentioned known example, this known example has twostages capable of independent operation. The example proposessynchronization between the two stages in a specific operation forpreventing any mutual interference between them and a reduction in sizeof the apparatus. This case may avoid any interference between the twostages and reduce the size of the apparatus. However, processing on onestage may be made to wait due to synchronization between the two stages,and a trade-off relationship is established between a reduction in sizeand an increase in throughput. Also, in this known example as well, theabove-mentioned reaction force problem still remains unsolved.

As another example similar to the method shown in FIG. 2B, there isavailable the method discussed in Japanese Patent No. 3,045,947.

This known example is directed to a stepper. Similarly to theabove-mentioned known example, the example has two stages capable ofindependent operation and proposes parallel stepwise operation of thetwo stages below exposure and measurement positions. This known exampledoes not describe the structures of the two stages, and their detailsare unknown. Similarly to the method in FIG. 2B, it seems difficult toattain a stage performance as high as that of a single stage by theeffects of the mutual reaction forces of the two stages.

(B) Two Completely Independent Stages

FIG. 2C shows the arrangement of improved method 2 in a conventionalsemiconductor exposure apparatus. Reference numeral 40 denotes anexposure wafer; 41, an exposure chuck; 42, an exposure fine adjustmentstage; 43, an exposure coarse adjustment stage; 44, an exposure waferstage surface plate; 50, a measurement wafer; 51, a measurement chuck;52, a measurement fine adjustment stage; 53, a measurement coarseadjustment stage; and 54, a measurement wafer stage surface plate.

The semiconductor exposure apparatus using this method has twocompletely independent stages. After alignment and focus measurements onthe measurement stage side, a wafer is loaded to the exposure stage sidetogether with a chuck to perform exposure on the exposure stage side. Asin improved method 1, reference marks (not shown) are formed on theedges of the chuck. The measurement and exposure stages measure thereference marks to accurately reflect alignment and focus measurementresults on the measurement stage in exposure on the exposure stage. Withthis operation, accurate alignment and focus can be implemented.

Method 2 has advantages and disadvantages as follows.

(Advantages)

Method 2 basically has advantages similar to those of method 1. In thismethod, two stages including stage surface plates are completelyindependent, and they never exert reaction forces on each other. Forthis reason, even if the speed of each stage increases, the precision ofscan synchronization between a reticle and a wafer can be kept high.Since method 2 basically adopts a wafer chuck transport method, it isrelatively easy to implement the chuck unloading function.

(Disadvantages)

Since method 2 requires two sets of completely independent stages, thesize of the apparatus increases. The lattices of the two sets of stagesneed to accurately coincide with each other. The two sets are slightlyseparated from each other, and it is more difficult than method 1 tocause the lattices to coincide with each other due to effects of thetemperature, air pressure, gas molecule composition, humidity, and thelike. Also, the method needs chuck transport. Since the two sets areseparated from each other, it is necessary to hold a wafer so as toprevent the position of the wafer on a chuck from shifting from thechuck during the chuck transport.

SUMMARY OF THE INVENTION

The present invention has as its object to propose a method of solvingthe above-mentioned problems of conventional semiconductor exposureapparatuses and solving the above-mentioned problems of improved methods1 and 2. More specifically, objects to be achieved by the presentinvention are as follows:

1. an increase in throughput;

2. facilitation of increasing the measurement precision of a focusdetection system;

3. relaxation of constraints on the design of a projection system;

4. facilitation of cleaning below the projection system;

5. facilitation of chuck cleaning;

6. a reduction in size of the apparatus; and

7. facilitation of supporting a load-lock.

The present invention eventually has as its object to implement acompact common platform which can be applied to various semiconductorexposure apparatuses whose exposure spaces are an outer air space,nitrogen-purged space, vacuum space, or the like, can relax constraintson the design of the projection system and focus detection system, andcan increase the speed and precision.

To solve the above-mentioned problems and to achieve the objects,according to the present invention, there is proposed a method ofarranging two independent fine adjustment stages on one coarseadjustment stage and simultaneously performing all of focus measurementand part of alignment measurement in parallel with an exposureoperation.

The present invention adopts a chuck transport method to easilyimplement the above-mentioned functions. The present invention proposesalignment of patterns on a wafer with a chuck before mounting the chuckon each fine adjustment stage.

According to the present invention, a more compact common platform,which can be applied to various semiconductor exposure apparatuses, canrelax constraints on the design of exposure and measurement units, andcan increase the speed and precision, can be implemented.

Other objects and advantages besides those discussed above shall beapparent to those skilled in the art from the description of a preferredembodiment of the invention which follows. In the description, referenceis made to the accompanying drawings, which form a part thereof, andwhich illustrate an example of the invention. Such an example, however,is not exhaustive of the various embodiments of the invention, andtherefore reference is made to the claims which follow the descriptionfor determining the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a schematic arrangement of the presentinvention;

FIG. 2A is a view showing a typical arrangement of a conventionalsemiconductor exposure apparatus, FIG. 2B is a view showing thearrangement of a conventional improved method 1, and FIG. 2C is a viewshowing the arrangement of a conventional improved method 2;

FIG. 3 is a plan view showing the schematic arrangement of asemiconductor exposure apparatus according to an embodiment of thepresent invention;

FIGS. 4A and 4B are plan and front views, respectively, of a coarseadjustment type;

FIGS. 5A and 5B are plan and front views, respectively, of aprealignment unit;

FIGS. 6A to 6D are a plan view, a front view in wafer loading, a frontview upon completion of coarse alignment, and a front view in waferunloading, respectively, of the coarse alignment unit;

FIGS. 7A to 7C are plan, front, and side views, respectively, showingthe structure of a chuck pipe line;

FIG. 8A is an enlarged view of the upper surface of a chuck, and FIG. 8Bis a sectional view including a chuck support unit on a fine adjustmentstage;

FIG. 9A is a view of a unit layout at a chuck loading position, andFIGS. 9B and 9C show how the chuck moves;

FIG. 10A is a view for explaining units at the chuck loading position,and FIGS. 10B and 10C show how the chuck moves;

FIG. 11 is a view for explaining the transport operation of a wafer andchuck;

FIG. 12 is a view for explaining the outline of coarse alignment;

FIG. 13 is a view for explaining a chuck reference mark;

FIG. 14 is a view for explaining the outline of exposure andfocus/alignment operations;

FIG. 15 is a view for explaining the outline of a chuck reference markmeasurement operation;

FIG. 16A is a view for explaining an exposure focus measurement region,and FIG. 16B is a view for explaining a measurement focus measurementregion;

FIGS. 17 to 19 are views for explaining the outline of operation of awafer stage unit;

FIG. 20 is a flow chart showing the operation flow of the wafer stageunit; and

FIG. 21 is a view for explaining chuck unloading.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described below in detailwith reference to the accompanying drawings.

[Outline of Present Invention (FIG. 1)]

FIG. 1 shows the arrangement of an exposure apparatus according to thepresent invention.

In FIG. 1, reference numeral 60 denotes an exposure wafer; 61, anexposure chuck; 62, an exposure fine adjustment stage; 70, a measurementwafer; 71, a measurement chuck (wafer chuck); 72, a measurement fineadjustment stage; 73, a coarse adjustment stage which bears the exposurefine adjustment stage 62 and measurement fine adjustment stage 72 andcan move horizontally; and 110, a coarse alignment unit arranged outsidethe coarse adjustment stage 73.

In the semiconductor exposure apparatus according to the presentinvention, the two fine adjustment stages 62 and 72 are mounted on theone coarse adjustment stage 73. The semiconductor exposure apparatus isarranged to simultaneously perform exposure and focus measurements atexposure and measurement positions by operation of the one coarseadjustment stage. When an alignment shot of the measurement wafer 70comes to near the measurement point during exposure of the exposurewafer 60, the exposure is temporarily interrupted to perform alignmentmeasurement.

A wafer having undergone alignment and focus measurements at themeasurement position on the measurement fine adjustment stage 72 issequentially transferred to the exposure position on the exposure fineadjustment stage 62 together with the measurement chuck 71, as indicatedby an arrow. Exposure operation of this wafer is performed in parallelwith measurement operation of the next wafer. This makes it possible tosimultaneously perform exposure and measurement by operation of the onecoarse adjustment stage and implement a compact high-speed exposureapparatus.

To increase the precision of focus measurement and the speed ofalignment measurement, patterns on respective wafers at the exposure andmeasurement positions preferably always have a predetermined positionalrelationship. For this reason, each pattern on the corresponding waferis aligned with respect to a chuck in the coarse alignment unit 110before loading onto the fine adjustment stages.

The conventional arrangement described in “(A) Place Two CoarseAdjustment Stages on Same Surface Plate” drives two large coarseadjustment stages. In contrast to this, the semiconductor exposureapparatus according to the present invention uses two movable units ofrespective small fine adjustment stages while the units are almostfixed, thus preventing stage interference. In other words, thesemiconductor exposure apparatus adopts a method of aligning in advancethe patterns on the wafers on the two fine adjustment stages with eachother to implement parallel exposure and measurement operations on thefine adjustment stages whose driving strokes are short.

The present invention incorporates various structural implementations,in addition to the above-mentioned ones. These implementations will bedescribed specifically in the following embodiment.

[Description of Detailed Embodiment]

A semiconductor exposure apparatus according to an embodiment of thepresent invention is a scan-type one which uses an F₂ excimer laser as alight source. Since F₂ excimer laser beams are absorbed by oxygen in theair and attenuate, a space through which exposure light passes needs tobe purged with nitrogen. The semiconductor exposure apparatus of thisembodiment is arranged to purge with nitrogen a space through which allexposure light beams pass, including the periphery of a stage. Thepresent invention, however, is not limited to a semiconductor exposureapparatus which uses an F₂ excimer laser as a light source and can alsobe applied to EUV and EB exposure apparatuses.

[Outline of Semiconductor Exposure Apparatus (FIG. 3)]

FIG. 3 is a plan view showing the outline of the semiconductor exposureapparatus according to the embodiment of the present invention.

The semiconductor exposure apparatus of this embodiment comprisescomponents along the transport path of a wafer. In FIG. 3, referencenumeral 101 denotes a loading position of the wafer; 102, a wafer handwhich transports the wafer; 103, a loading load-lock chamber; 104, aprealignment unit; 105, a loading hand; 110, the coarse alignment unit;111, a coarse alignment scope of the coarse alignment unit 110; 112, acoarse focus sensor unit of the coarse alignment unit 110; 113, a coarsechuck stage of the coarse alignment unit 110; 120, a loading plate; 121,a chuck loading position on the loading plate 120; 122, a chuckunloading position on the loading plate 120; 123, a chuck hand whichtransports a chuck; 130, an unloading load-lock chamber; 131, anunloading hand capable of transporting the wafer or chuck; 132, anunloading Z unit which vertically drives the wafer or chuck; 140, anopen cassette; 190, outer air gate valves of the loading and unloadingload-lock chambers; 191, purge gate valves of the loading and unloadingload-lock chambers; 192, support columns of a structure (not shown)which holds a projection system 4 and an alignment scope 5; 193, loadingplate position sensors attached to the coarse adjustment stage 73 tomeasure the position of the loading plate 120; 194, a nitrogen purgespace; and 195, nitrogen purge space partition walls.

Reference numeral 4 denotes the projection system; 5, the alignmentscope; 62, the exposure fine adjustment stage; 72, the measurement fineadjustment stage; and 73, the coarse adjustment stage, as described withreference to FIGS. 1 and 2A.

(Outline of Operation)

In the semiconductor exposure apparatus of this embodiment, a wafer isfirst loaded to the loading position 101. A temperature-adjusting unit(not shown) is provided below the loading position 101 to adjust thetemperature of the loaded wafer so as to fall within a predeterminedrange. When the temperature of the wafer falls within the predeterminedrange, the wafer hand 102 moves the wafer to the prealignment unit 104in the loading load-lock chamber 103. The prealignment unit 104 measuresthe outer shape of the wafer and aligns the wafer such that a notchformed in the wafer faces in a predetermined rotational direction. Theprealignment operation and purge of the loading load-lock chamber 103with nitrogen are simultaneously performed, thereby preventing any lossin time.

When the prealignment by the prealignment unit 104 is completed, theloading hand 105 moves the wafer from the prealignment unit 104 onto achuck on standby in the coarse alignment unit 110. The coarse alignmentunit 110 roughly measures the position of a pattern of the wafer on thechuck and the height of the entire wafer and performs alignment suchthat chuck reference marks on the edges of the chuck and a predeterminedpattern of the wafer have a predetermined relative positionalrelationship. After that, the wafer is moved to the chuck loadingposition 121 on the loading plate 120, while being chucked by the chuckhand 123. Movement of the loading plate 120 to the side of the coarseadjustment stage 73 causes the chuck at the chuck loading position 121to move onto the measurement fine adjustment stage 72 on standby. Atthis position, the measurement fine adjustment stage 72 moves upward andreceives the chuck from the loading plate 120.

Then, the loading plate 120 retreats to the original position shown inFIG. 3. The wafer on the measurement fine adjustment stage 72 undergoesfocus and alignment measurements (to be described later) and moves ontothe exposure fine adjustment stage 62 through the loading plate 120 toperform exposure. Upon completion of the exposure, the chuck moves tothe chuck unloading position 122 through the loading plate 120.

The chuck is returned to the coarse alignment unit 110 by the chuck hand123, and only the wafer is pulled out by the unloading hand 131 in theunloading load-lock chamber 130. After the unloading load-lock chamber130 is purged with dry air, the wafer hand 102 returns the wafer to theloading position 101 and issues an unloading command to an externalprocessing apparatus.

[Outline of Arrangement and Operation of Wafer Stage (FIGS. 4A and 4B)]

The arrangement and operation of a wafer stage will be described indetail.

FIGS. 4A and 4B are plan and front views, respectively, of the coarseadjustment stage according to the embodiment of the present invention.

In FIGS. 4A and 4B, reference numeral 73 denotes the coarse adjustmentstage; 61, the exposure chuck; 62, the exposure fine adjustment stage;71, the measurement chuck; 72, the measurement fine adjustment stage;201, an upper X counter mass; 202, a lower X counter mass; 203, a left Ycounter mass; 204, a right Y counter mass; 205, an X driving beam; 206,a Y driving beam; 207, X linear motor magnets; 208, Y linear motormagnets; 210, laser interferometer exposure bar mirrors; 211, laserinterferometer measurement bar mirrors; 221, an exposure laserinterferometer beam X; 222, an exposure laser interferometer beam Y;223, a measurement laser interferometer beam X; 224, a measurement laserinterferometer beam Y; 230, a wafer stage surface plate; 231, waferstage dampers; and 232, a wafer stage base plate.

(Outline of Operation)

In the semiconductor exposure apparatus of this embodiment, the waferstage surface plate 230 is levitated by a jet of nitrogen with respectto the wafer stage surface plate 230. The semiconductor exposureapparatus is capable of moving the coarse adjustment stage 73 in the Ydirection through the Y driving beam 206 by driving the Y linear motormagnets 208 with Y linear motor coils (not shown) and in the X directionthrough the X driving beam 205 by driving the X linear motor magnets 207with X linear motor coils (not shown).

The two fine adjustment stages, i.e., the exposure fine adjustment stage62 and measurement fine adjustment stage 72 are mounted on the coarseadjustment stage 73. Use of laser interferometers allows X and Yposition measurements and fine driving of each fine adjustment stage. Afine adjustment stage movable unit (not shown) in each fine adjustmentstage can perform fine driving in the height (Z-axis) and tiltdirections by an internal linear motor. The coarse adjustment stage 73has four counter masses, i.e., the upper X counter mass 201, lower Xcounter mass 202, left Y counter mass 203, and right Y counter mass 204mounted in a linear motor unit (not shown) to cancel any reaction forcegenerated upon driving. Driving these counter masses in a directionopposite to that of the coarse adjustment stage 73 being driven cancelsany reaction force generated by the coarse adjustment stage 73.

The coarse adjustment stage 73 is arranged on the wafer stage surfaceplate 230, which is placed on the floor through the wafer stage dampers232 for cutting off floor vibrations.

The above-mentioned stages have the following features.

(1) Driving Stroke of each Fine Adjustment Stage

The driving stroke of the measurement fine adjustment stage 72 is set tobe larger than that of the exposure fine adjustment stage 62. This isbecause the measurement fine adjustment stage 72 receives a wafer chuckfrom outside the stage and needs driving to correct a relatively largeerror generated upon loading. The exposure fine adjustment stage 62 mustmaintain synchronization between a reticle and wafer at high precisionin exposure, and has a short driving stroke to achieve a quick response.

(2) Mechanical Resonance Frequency

The mechanical resonance frequencies of the measurement fine adjustmentstage 72 and exposure fine adjustment stage 62 are set to differ fromeach other. This is to prevent any mutual interference in alignment ofeach fine adjustment stage.

(3) Dynamic Control of Control Parameters

In exposure operation, the control gain (parameter) of the exposure fineadjustment stage 62 is set to be high while that of the measurement fineadjustment stage 72 is set to be low. In alignment measurement to beperformed during the exposure operation, the control gain of theexposure fine adjustment stage 62 is set to be low while that of themeasurement fine adjustment stage 72 is set to be high. This is becausethe exposure fine adjustment stage 62 requires high-precisionsynchronous control of the wafer and reticle in the exposure operationwhile the measurement fine adjustment stage 72 requires the accurateposition information of the wafer in the alignment measurement.

In the above-mentioned setting, the control gain of one fine adjustmentstage is set to be high while that of the other is set to be low. Thisis intended to prevent unnecessary vibrations from being transmittedfrom the measurement fine adjustment stage 72 to the exposure fineadjustment stage 62 in exposure or from the exposure fine adjustmentstage 62 to the measurement fine adjustment stage 72 in measurement.

(4) Calibration of Bar Mirror for each Fine Adjustment Stage

Each of the exposure fine adjustment stage 62 and measurement fineadjustment stage 72 is arranged to control its movable portion at theupper portion to be locked with respect to its fixed portion at thelower portion. In this locked state, the coarse adjustment stage 73 isdriven in the X and Y directions, and laser interferometers measure theposition of each fine adjustment stage. This makes it possible tomeasure the relative error at each position in the X direction betweenthe X-measurement bar mirrors of the fine adjustment stages and therelative error at each position in the Y direction between theY-measurement bar mirrors of the fine adjustment stages. The relativeerrors between the bar mirrors are used to cause the stage coordinatesof the measurement unit and those of the exposure unit to preciselycoincide with each other.

(5) Constraints on Chuck Mounting

The coarse adjustment stage 73 is driven only when both the fineadjustment stages bear or do not bear respective chucks. This is becausethe weight balance of the coarse adjustment stage 73 needs to be keptconstant to drive the coarse adjustment stage 73 at high speed and highprecision.

(6) Loading Plate Tracking Function

The loading plate 120 is fixed on the wafer stage base plate 232, andthe coarse adjustment stage 73 is placed on the wafer stage surfaceplate 230 on the wafer stage dampers. For this reason, the loading plate120 and each fine adjustment stage needs to have a predeterminedpositional relationship in transferring a chuck between them. Toimplement this, the loading plate position sensors 193 are arranged onthe coarse adjustment stage 73. In chuck transfer, each fine adjustmentstage is finely driven such that the loading plate 120 and the movableunit at the upper portion of the fine adjustment stage have apredetermined positional relationship.

[Outline of Arrangement and Operation of Prealignment (FIGS. 5A and 5B)]

FIGS. 5A and 5B are plan and front views, respectively, of theprealignment unit of the semiconductor exposure apparatus according tothe embodiment of the present invention.

As shown in FIGS. 5A and 5B, reference numeral 103 denotes the loadingload-lock chamber; 190, the outer air gate valves; 191, the purge gatevalves; 300, a wafer during prealignment; 301, a prealignmentlight-projecting unit; 302, prealignment sensors; 303, a sheet glass (onthe light-projecting unit side); 304, a sheet glass (on the sensorside); 305, a sensor support unit; 306, a purge seal unit; 307, arotation mechanism unit; 308, a Z driving unit; and 309, a wafer supportunit.

(Outline of Operation)

After the loading load-lock chamber 103 is purged with dry air, theouter air gate valves 190 are opened, and the wafer 300 is loaded to thewafer support unit 309 by the wafer hand 102. At this time, theprealignment light-projecting unit 301 and prealignment sensors 302measure the circumferential edge position of the wafer 300 being loaded.The wafer 300 is aligned by stretching and contracting operation androtation operation of the wafer hand 102 such that the center of thewafer 300 almost coincides with that of the wafer support unit 309. Thewafer 300 is placed on the wafer support unit 309.

The rotation mechanism unit 307 on the outer air side rotates the wafer300 through the purge seal unit 306, and the prealignment sensors 302measure the circumferential edge position of the wafer during therotation. This measurement enables more precise measurement of the waferedge position and the notch (or orientation flat) position. Hence, therotation mechanism unit 307 rotates the wafer such that the notch facesin a predetermined direction.

In the prealignment unit 104, the volume of the loading load-lockchamber 103 needs to be minimized to minimize the nitrogen purge time.To implement this, the prealignment light-projecting unit 301 andprealignment sensors 302 are arranged outside the loading load-lockchamber 103 to receive detection light into the loading load-lockchamber 103 through the sheet glass 303 (on the light-projecting unitside) and sheet glass 304 (on the sensor side).

Outer shape errors in the X and Y directions after the notch is rotatedin a predetermined direction will be described later in [Outline ofCoarse Alignment].

[Outline of Arrangement and Operation of Coarse Alignment Unit (FIGS. 6Ato 6D)]

The coarse alignment unit performs three major operations as follows.

(1) The coarse alignment unit performs alignment such that a referencemark on the chuck and a prealignment mark on the wafer have apredetermined relative positional relationship. The coarse alignmentunit stores shifts in the X, Y, and θ directions from the targetrelative position in this alignment.

(2) The coarse alignment unit aligns the θ direction of the referencemark on the chuck with the reference position of the coarse alignmentunit. The coarse alignment unit stores shifts in the X and Y directionsfrom the target position.

(3) The coarse alignment unit measures the height of the upper surfaceof the reference mark on the chuck and that of the upper surface of thewafer and stores the measurement results.

The above-mentioned functions are very important for the semiconductorexposure apparatus according to the present invention. This is becausemeasurements to be described later, i.e., simultaneous measurement ofreference marks on the exposure and measurement chucks, focusmeasurement to be performed in parallel with exposure operation on theexposure side, and alignment measurement on the measurement side to beperformed while the exposure operation on the exposure side istemporarily interrupted are based on the premise that patterns on thewafers on the exposure and measurement sides have a predeterminedpositional relationship at relatively high precision. The coarsealignment unit described herein performs measurements required toimplement this.

The arrangement of the coarse alignment unit will be described below.

FIGS. 6A to 6D are a plan view, a front view in wafer loading, a frontview upon completion of coarse alignment, and a front view in waferunloading, respectively, of the coarse alignment unit 110 of thesemiconductor exposure apparatus according to the embodiment of thepresent invention.

As shown in FIGS. 6A to 6D, reference numeral 110 denotes the entirecoarse alignment unit; 111, the coarse alignment scope; 112, the coarsefocus sensor unit; 113, the coarse chuck stage which can move in the Xdirection; 401, an objective lens for measuring a chuck reference markof the coarse alignment scope 111; 402, an objective lens for detectinga wafer prealignment mark of the coarse alignment scope 111; 403, (five)fiber sensors of the coarse focus sensor unit 112 to measure the heightof the upper surface of a chuck reference plate (to be described later)and the upper surface of a wafer; 405, a chuck during coarse alignment;406, a wafer during coarse alignment; 407, a chuck support unit whichholds the chuck 405 from below and can perform fine vertical androtation driving; and 408, three wafer support pins which can finelydrive in the X, Y, and θ directions and can operate in the Z direction.

The coarse alignment unit 110, loading hand 105, chuck hand 123, andloading plate 120 are fixed on the wafer stage base plate 232 so as toprevent vibrations generated upon coarse alignment operation (to bedescribed later) and the like from being directly transmitted to, e.g.,the coarse adjustment stage 73 on the wafer stage surface plate 230.

(Outline of Operation)

In FIGS. 6A to 6D, the five fiber sensors 403 are arranged in the coarsefocus sensor unit 112 almost equidistantly. The two outermost fibersensors (top and bottom ones in FIG. 6A) are used to measure the heightof the upper surface of the chuck reference plate (to be describedlater) on the chuck 405 while the three inner fiber sensors are used tomeasure the height of the upper surface of the wafer 406 on the chuck405. When the wafer 406 passes below the coarse focus sensor unit 112,the heights of the upper surfaces of the chuck reference plate and waferare measured. Resultant measurement values are used to performcorrection driving in the Z and tilt directions after the chuck 405 ismounted on the measurement fine adjustment stage 72 on the coarseadjustment stage 73 and align the upper surface of the wafer within arange which allows focus measurement in final focus measurement on thecoarse adjustment stage.

The objective lens (for chuck reference marks) 401 of the coarsealignment scope 111 in FIGS. 6A to 6D is fixed to the coarse alignmentscope 111 and is used to measure two chuck reference marks (to bedescribed later) at the upper left and right positions on the chuckreference plate on the chuck.

The objective lens (for wafer marks) 402 of the coarse alignment scope111 can drive in the Y direction, as indicated by an arrow. Theobjective lens 402 moves to a position in the Y direction where aprealignment mark (not shown) on the wafer 406 having been specified bythe operator of the apparatus can be observed. The objective lens 402 isused to measure the position of the prealignment mark. Prealignmentmarks are generally located at two points on a wafer. The wafer 406temporarily stops four times below the coarse alignment scope 111 tomeasure the positions of the prealignment marks (twice) and chuckreference marks (twice).

The coarse chuck stage 113 has the three wafer support pins 408, whichcan finely drive in the X, Y, and θ directions and can also drivevertically, as indicated by inner arrows. Assume that measurementresults of the chuck reference marks and prealignment marks show thatthe prealignment marks on the wafer are not located at predeterminedpositions relative to the reference marks on the chuck and are separatedfrom the reference marks by distances of more than a tolerance. In thiscase, the three wafer support pins 408 lift the wafer 406 from the chuck405, perform for the wafer 406 fine correction driving in the X, Y, andθ directions so as to attain a predetermined positional relationship,and return the wafer 406 onto the chuck 405. With this operation, theprealignment marks on the wafer have a predetermined relative positionalrelationship with the chuck reference marks on the chuck.

An error in the θ direction of each chuck reference mark is obtainedfrom measurement results of the two chuck reference marks. Such an erroris eliminated by finely rotating the coarse chuck stage 113.

After the above-mentioned operation, similar operation is repeated suchthat the prealignment marks on the wafer are located at predeterminedpositions relative to the chuck reference marks on the chuck, and anerror in the θ direction of each chuck reference mark is eliminated.

Residual errors after the above-mentioned operation, i.e., the followingtwo errors (1) and (2) will be described later in [Outline of CoarseAlignment]:

(1) residual error amounts in the X, Y, and θ directions of theprealignment marks with respect to the chuck reference marks; and

(2) residual error amounts in the X, Y, and θ directions of the chuckreference marks with respect to the coarse alignment unit.

FIG. 6B shows wafer loading. The three wafer support pins 408 extendupward from the coarse chuck stage 113 through the chuck 405. The waferis placed on the three wafer support pins by the loading hand 105. Thethree wafer support pins 408 retract into the coarse chuck stage 113 andpass the wafer 406 to the chuck 405. Then, the coarse chuck stage 113starts moving to the left. When the wafer 406 comes to below the coarsefocus sensor unit 112, the fiber sensors 403 start measuring the heightsof the upper surfaces of the chuck reference plate and wafer.

During the measurement, the chuck reference marks on the chuck referenceplate and prealignment marks on the wafer 406 come to below the coarsealignment scope 111. Then, the coarse alignment scope 111 captures theimage information of their patterns and measures the positions of thechuck reference marks and prealignment marks on the wafer.

At this time, the height of the chuck reference plate and those of theprealignment marks on the wafer are already obtained by the fibersensors 403. The detection surface is always kept at the measurementimage plane position of the coarse alignment scope 111 by driving thechuck 405 in the Z direction with the coarse chuck stage 113.

Correction driving to follow is as described above. The chuck will bedescribed later in detail. A chuck used in the semiconductor exposureapparatus of this embodiment needs to be vacuum-chucked and fixed to thecoarse chuck stage 113, measurement fine adjustment stage 72, exposurefine adjustment stage 62, chuck hand 123, or loading plate 120. Thelower surface of the chuck has a planar structure. For this reason,while the chuck moves among a plurality of positions, it may shift froma predetermined position in each unit of the apparatus due to along-term accumulation of transport errors.

To prevent this shift, the semiconductor exposure apparatus of thisembodiment detects positional shifts in the X, Y, and θ directions ofthe chuck using measurement results of the two stage reference markpositions. The semiconductor exposure apparatus eliminates a shift inthe X direction by shifting the X position of the coarse chuck stage 113in moving the chuck to the chuck hand 123, a shift in the Y direction byshifting the Y position of the chuck hand 123 in moving the chuck to thechuck hand 123, and a shift in the θ direction by rotating a chucksupport unit 412.

The overall description will be given in [Outline of Coarse Alignment].

FIG. 6C shows how the chuck is moved from the coarse alignment unit 110to the chuck hand 123 after the operation in the coarse alignment unit110. FIG. 6D shows how the exposed wafer is unloaded.

As shown in FIGS. 6C and 6D, the coarse chuck stage 113 lifts the wafer406 by the three wafer support pins 408 such that the unloading hand 131can pick up the wafer 406 on the chuck 405, similarly to wafer loading.Though not shown in FIGS. 6C and 6D, in unloading the chuck 405, theunloading hand 131 is arranged to insert its hand unit into the chucksupport unit 412 below the chuck 405 and unload the chuck 405 from thecoarse chuck stage 113.

[Outline of Structure of Chuck Pipe Line (FIGS. 7A to 7C and 8A and 8B)]

The structure of a chuck pipe line used in the semiconductor exposureapparatus of this embodiment will be described below.

The semiconductor exposure apparatus of this embodiment adopts a methodof transporting a wafer together with a chuck. To maintain the positionof the wafer during chuck transport, a unique pipe mechanism is employedinside the chuck.

FIGS. 7A to 7C are plan, front, and side views, respectively, showingthe structure of the chuck pipe line. FIGS. 8A and 8B are an enlargedview of the upper surface of a chuck and a sectional view including achuck support unit on a fine adjustment stage.

As shown in FIGS. 7A to 7C, reference numeral 500 denotes a chuck; 501,holes through which the three wafer support pins 408 of the coarse chuckstage 113 pass in the coarse alignment unit 110; 502, wafer vacuum(Vac.) portions to which wafer Vac. pipes from the chuck hand 123 areconnected; 503, wafer Vac. valves at the inlets of the wafer Vac.portions 502; 504, wafer Vac. portions to which wafer Vac. pipes fromthe loading plate 120 are connected; 505, wafer Vac. valves at theinlets of the wafer Vac. portions 504; 506, a wafer Vac. portion towhich a wafer Vac. pipe from the exposure fine adjustment stage 62 ormeasurement fine adjustment stage 72 is connected; 507, a wafer Vac.valve at the inlet of the wafer Vac. portion 506; and 508, a waferchucked and held on the chuck 500 by a Vac. (negative pressure).

In FIG. 8A, chuck reference plates 600 are arranged at the four cornersof the chuck. Their upper surfaces are used as references of height atthe exposure and measurement positions. Chuck reference marks (to bedescribed later) are formed in the chuck reference plates 600.

In FIG. 8B, reference numeral 510 denotes chuck pins arranged within aregion immediately below the wafer 508 and on the upper surface of thechuck; 511, a fine adjustment top plate attached to the upper surface ofthe fine adjustment stage movable unit at the upper portion of each ofthe two fine adjustment stages; 512, top plate pins arranged within aregion immediately below the chuck 500 and on the upper surface of thefine adjustment top plate 511; 520, a fine adjustment wafer Vac. forchucking the wafer on the chuck by a Vac.; and 521, a fine adjustmentchuck Vac. for fixing the chuck 500 on the fine adjustment top plate511.

(Outline of Operation)

The chuck needs to move on the coarse chuck stage 113, chuck hand 123,loading plate 120, measurement fine adjustment stage 72, and exposurefine adjustment stage 62 while holding the wafer. For this reason, awafer chucking Vac. can be supplied from the above-mentioned units. Whenthe chuck is to be moved between two of the units, it must receive Vac.simultaneously from the two units. The chuck of this embodiment has aplurality of Vac. inlets and corresponding Vac. valves inside the Vac.inlets to smoothly switch between Vac. supply lines in this case. Thesevalves allow switching between the Vac. supply lines without a specialswitching mechanism.

The fine adjustment top plate 511 which fixes the chuck by chucking witha Vac. has the top plate pins 512 on its upper surface, similarly to thechuck. This is intended to minimize the effect of any dust or the likeattached to the lower surface of the chuck.

[Outline of Arrangement and Operation of Chuck Switching Mechanism(FIGS. 9A to 9C and 10A to 10C)]

FIGS. 9A to 9C and 10A to 10C show an example of a chuck transportmethod according to the embodiment of the present invention. FIGS. 9A to9C and 10A to 10C illustrate how the chuck 500 is mounted from the chuckhand 123 through the loading plate 120 onto the fine adjustment topplate 511 on each fine adjustment stage.

FIG. 9A is a plan view showing the chuck hand 123 and loading plate 120at the chuck loading position 121; and FIGS. 9B and 9C show how thechuck moves from the chuck hand 123 to the loading plate 120. FIG. 10Ais a plan view showing the loading plate 120 and fine adjustment topplate 511 at the chuck loading position 121; and FIGS. 10B and 10C showhow the chuck moves from the loading plate 120 to the fine adjustmenttop plate 511.

Reference numeral 530 denotes chuck support units which receive thechuck 500 from the chuck hand 123 on the loading plate 120 and hold it;540, chuck Vac. portions which supply Vac. for chucking and holding thechuck 500 on the chuck support units 530 on the loading plate 120; and541, chuck Vac. portions which supply Vac. for chucking and holding thechuck 500 on the chuck hand 123.

(Outline of Operation)

Operation of moving the chuck from the chuck hand 123 through theloading plate 120 onto the fine adjustment top plate 511 will bedescribed with reference to FIGS. 9B, 9C, 10B and 10C.

(1) On Chuck Hand

A state wherein the chuck 500 is on the chuck hand 123 is shown in FIG.9B.

In this state, the chuck 500 is mounted on the chuck hand 123. The chuck500 is chucked on the chuck hand 123 by the chuck Vac. portions 541 witha Vac. and is fixed.

The wafer 508 is chucked on the chuck 500 by a Vac. from the wafer Vac.portions 502 and is fixed.

In this state, the chuck support units 530 on the loading plate 120 donot come into contact with the chuck 500.

(2) On Loading Plate

A state wherein the chuck 500 is on the loading plate 120 is shown inFIG. 9C.

This state is implemented by the following operation. In the state shownin FIG. 9B, the wafer Vac. portions 504 and chuck Vac. portions 540arranged on the chuck support units 530 on the loading plate 120 arebrought into a Vac. state. The chuck hand 123 is moved downward to apredetermined position, and the chuck Vac. portions 541 and the waferVac. portions 502 on the chuck hand 123 side are switched from the Vac.state to an atmospheric state. The chuck hand 123 is further moveddownward.

A chuck holding unit of the chuck hand 123 has a vertical frictionmechanism (not shown) to prevent an overload of a predeterminedmagnitude or more on the chuck hand 123 and chuck support units 530 inthe above-mentioned operation.

(3) Above Fine Adjustment Stage

When the chuck 500 is fixed on the loading plate 120, the loading plate120 moves from outside the coarse adjustment stage 73 onto the coarseadjustment stage 73.

In this state, the coarse adjustment stage 73 moves a movable unit atthe upper portion of the measurement fine adjustment stage 72 on thecoarse adjustment stage 73 downward and moves to a position where itfits into the loading plate 120. The state at this time is shown in [3.Above Fine Adjustment Stage]

In this state, the chuck 500 is held on the chuck support units 530 onthe loading plate 120 by the chuck Vac. portions 540, as described inFIG. 10B. The wafer 508 is chucked and held with a Vac. on the chuck bythe wafer Vac. portions 504 on the chuck support units 530 on theloading plate 120.

(4) On Fine Adjustment Stage Top Plate

A state wherein the chuck 500 moves onto the fine adjustment top plate511 is shown in FIG. 10C.

This state is implemented by the following operation. In the state shownin FIG. 10B, the fine adjustment wafer Vac. 520 and fine adjustmentchuck Vac. 521 on the fine adjustment top plate 511 side are broughtinto a Vac. state. The fine adjustment top plate 511 is moved upward toa predetermined position, and the chuck Vac. portions 540 and the waferVac. portions 504 on the loading plate 120 side are switched from theVac. state to an atmospheric state. The fine adjustment top plate 511 isfurther moved upward.

[Transport Operation of Wafer and Chuck (FIG. 11)]

The operations of the units have been described above. Operation oftransporting a wafer and chuck by the entire apparatus, in which theseoperations are combined, will be described with reference to FIG. 11.Reference numerals in FIG. 11 denote the chronological order andcorrespond to the parenthesized numbers in the following description.Narrow lines indicate wafer movement while wide lines indicate chuckmovement.

(1) The wafer is loaded to the loading position 101 by an externalapparatus (e.g., a coater/developer).

A temperature-adjusting function (not shown) is also arranged at thisposition. The wafer is made to stand by until its temperature reaches apredetermined value.

(2) The wafer hand 102 loads the wafer from the loading position 101 tothe prealignment unit 104 in the loading load-lock chamber 103.

At this time, the wafer hand 102 performs rough alignment using theprealignment sensors 302. Concurrently with the start of nitrogen purge,the edge position of the wafer is measured while the wafer is rotated.On the basis of the measurement result, a notch or orientation flat ismade to face in a predetermined rotational direction, and error amountsin the X and Y directions are calculated.

(3) The loading hand 105 moves the wafer from the prealignment unit 104onto the chuck on the coarse chuck stage 113 of the coarse alignmentunit 110. At this time, as for the error amounts in the X and Ydirections calculated in (2), the error in the Y direction is correctedby correcting the pick-up position of the loading hand while the errorin the X direction is corrected by correcting the X position of thecoarse chuck stage 113 in wafer mounting. Note that the wafer istransported on the chuck in subsequent operation.

(4) The coarse alignment unit 110 measures the height of the entirewafer surface by using a chuck reference plate as a reference when thecoarse chuck stage 113 passes below the coarse focus sensor unit 112 andcoarse alignment scope 111. The coarse alignment unit 110 detects thepositions of chuck reference marks on the chuck reference plate andprealignment marks in the wafer and performs correction driving with thethree wafer support pins 408 such that the prealignment marks on thewafer are located at predetermined positions relative to the chuckreference marks. An error in the θ direction of each chuck referencemark is also corrected by this correction driving.

(5) When the coarse alignment operation ends, the coarse chuck stage 113moves to the transfer position of the chuck hand 123.

(6) The chuck hand 123 moves the chuck on the coarse chuck stage 113 tothe chuck loading position 121 on the loading plate 120 while the chuckholds the wafer thereon. At this time, as for the error amounts in the Xand Y directions of the chuck reference marks calculated in (4), theerror in the X direction is eliminated by correcting and driving theposition of the coarse chuck stage 113 in the X direction in thetransfer operation while the error in the Y direction is eliminated bycorrecting and driving the position of the chuck hand 123 in the Ydirection in the transfer operation.

(7) The loading plate 120 moves to the coarse adjustment stage 73 side(apparatus center side) and at this position, moves the chuck from theloading plate 120 onto the fine adjustment top plate 511 on themeasurement fine adjustment stage 72. Upon completion of the movement,the loading plate 120 externally retreats from the coarse adjustmentstage 73. After that, the measurement fine adjustment stage 72 issubjected to focus/alignment measurement operation, and a detaileddescription thereof will be given later.

(8) Upon completion of the measurement operation, the loading plate 120moves to the side of the coarse adjustment stage 73, which temporarilyreturns the chuck to the loading plate 120.

(9) The coarse adjustment stage 73 passes the chuck to the loading plate120. The empty coarse adjustment stage 73 moves in a downward directionwith respect to the sheet surface of FIG. 11 and receives the chuck fromthe loading plate 120. With this operation, the chuck having undergonemeasurement moves from the measurement fine adjustment stage 72 onto theexposure fine adjustment stage 62. After that, the loading plate 120retreats externally. The chuck having moved to the exposure fineadjustment stage 62 is subjected to exposure operation.

(10) Upon completion of the exposure operation, the loading plate 120moves again to the coarse adjustment stage 73 side, and the chuck havingundergone exposure moves to the chuck unloading position 122 on theloading plate 120.

(11) The chuck having moved to the loading plate 120 externally retreatsfrom the coarse adjustment stage 73 by external movement of the loadingplate 120.

(12) The chuck hand 123 returns the chuck having retreated from thecoarse adjustment stage 73 to the coarse chuck stage 113 of the coarsealignment unit 110.

(13) The coarse chuck stage 113 moves to the wafer unloading positionand at this position, causes the three wafer support pins 408 to extendupward, thereby lifting the wafer from the chuck.

(14) The unloading hand 131 in the unloading load-lock chamber 130recovers the wafer into the unloading load-lock chamber. After theunloading load-lock chamber 130 recovers the wafer, the atmosphere inthe unloading load-lock chamber 130 is purged of nitrogen with dry air.Then, the wafer is moved upward by the unloading Z unit 132 at thecentral portion.

(15) The wafer hand 102 unloads the wafer from the unloading Z unit 132and moves it to the loading position 101.

(16) In parallel with the operations in (14) and (15), the empty chuckfrom which the wafer has been removed by the unloading hand 131 movesagain to the wafer loading position of the coarse alignment unit andwaits until the loading of the next wafer.

(17) The wafer having been returned to the loading position 101 isrecovered by an external apparatus.

The operation of the wafer and chuck has sequentially been describedmainly from the aspect of a transport operation. The units in an actualexposure apparatus operate in parallel. An explanation with an emphasison this parallel operation will be given after a description of theoperation of the stage unit in, e.g., alignment measurement andexposure.

[Outline of Coarse Alignment (FIG. 12)]

In this embodiment, as described above, the two fine adjustment stagesare arranged on the one coarse adjustment stage, thereby performingsimultaneous measurement of reference marks on the exposure andmeasurement chucks, focus measurement on the measurement side to beperformed in parallel with exposure operation on the exposure side, andalignment measurement on the measurement side to be performed while theexposure operation on the exposure side is temporarily interrupted. Toimplement these measurements on the coarse adjustment stage, thefollowing three conditions must be satisfied on the coarse adjustmentstage.

(1) Predetermined patterns of a wafer on the exposure fine adjustmentstage and those of a wafer on the measurement fine adjustment stage havea predetermined relative positional relationship.

(2) Chuck reference marks on the exposure fine adjustment stage andthose on the measurement fine adjustment stage have a predeterminedrelative positional relationship.

(3) Rough measurement of the height of the wafer on the measurement fineadjustment stage is completed, and tilt correction (global tiltcorrection) of the entire wafer can be performed.

The semiconductor exposure apparatus of this embodiment performs thefollowing coarse alignment and coarse focus measurement to satisfy theabove-mentioned conditions.

A coarse measurement system will be explained. Note that part of itsdescription may be repetitive.

The parenthesized numbers in FIG. 12 indicate correction drivingpositions where coarse alignment is performed and measurement positionswhere coarse focus measurement is performed in the followingdescription.

(Wafer Coarse Alignment)

Wafer coarse alignment consists of the following three steps, and a unitother than the coarse alignment unit performs part of the operation.

(1) Alignment in Prealignment Unit

When a wafer is to be loaded to the prealignment unit 104, the center ofthe wafer is set to the almost center of the wafer support unit 309 ofthe prealignment unit 104. Then, the position of a notch (or orientationflat) is detected, and the wafer is rotated such that the notch faces ina predetermined direction.

(2) Alignment at Wafer Loading Position in Coarse Alignment Unit

Outer shape errors in the X and Y directions after the notch is rotatedin a predetermined direction are eliminated at the wafer loadingposition of the coarse alignment unit. The error in the Y direction iseliminated by correcting the Y position of the loading hand 105 inloading while the error in the X direction is eliminated by correctingthe X position of the coarse chuck stage 113 in loading. On the basis ofthe outer shape measurement result, the wafer is loaded to a positionwhere the positions of prealignment marks in the wafer are located atpredetermined positions relative to chuck reference marks.

(3) Prealignment in Coarse Alignment Unit

It is difficult to cause the prealignment marks in the wafer to have apredetermined positional relationship with the chuck reference marks onthe basis of only the outer shape measurement result. For this reason,the coarse alignment unit measures the positions of the prealignmentmarks in the wafer. As needed, the three wafer support pins 408 lift thewafer to align the prealignment marks with the chuck reference marks.The positions of the prealignment marks are measured again. Thisoperation is repeated until a positional shift becomes equal to orsmaller than a predetermined tolerance.

Note that above-mentioned operation is performed simultaneously withreference mark measurement and correction driving of an error in the θdirection of a chuck shown in (5) below.

Correction driving for residual error amounts in the X, Y, and θdirections from a predetermined relative position is performed after thechuck is mounted on the measurement fine adjustment stage. Thecorrection driving is performed such that the wafer on the exposure fineadjustment stage and its patterns have a predetermined relativepositional relationship in fine alignment measurement on the measurementfine adjustment stage (to be described later).

(Chuck Coarse Alignment)

Chuck coarse alignment includes the following two steps.

(4) Measurement of Reference Mark in Empty Chuck

The empty chuck from which the wafer has been removed by the unloadinghand 131 at the wafer unloading position undergoes chuck reference markposition measurement by the coarse alignment scope 111 of the coarsealignment unit 110 and obtains positional shift amounts before loadingthe next wafer. The positional shift amount in the θ direction iseliminated by rotating the chuck on the coarse chuck stage. Thepositional shifts in the X and Y directions are eliminatedsimultaneously with correction of the Y position of the loading hand andthe X position of the coarse chuck stage in the wafer loading describedabove. This reduces a correction amount after wafer loading.

(5) Reference Mark Measurement after Wafer Loading

The positions of the chuck reference marks are measured simultaneouslywith the wafer prealignment in (3) to obtain positional shift amounts ofthe chuck. Out of the positional shift amounts, the error in the θdirection is eliminated by finely rotating the coarse chuck stage 113.To eliminate the residual error amounts in the X and Y directions, the Yposition of the chuck hand 123 and the X position of the coarse chuckstage 113 are corrected in loading the chuck to the chuck loadingposition 121 on the loading plate 120. With this operation, the chuckreference marks are located at predetermined positions on the chuckloading position 121.

A residual error amount in the θ direction after fine rotation of thecoarse chuck stage 113 will be described. The measurement fineadjustment stage 72 is rotated in an opposite direction by the residualerror amount in loading the chuck to the measurement fine adjustmentstage 72 and is returned to the original position after the chuckloading. This reduces the residual error amount in the θ direction afterloading the chuck to the measurement fine adjustment stage 72.

(Wafer Coarse Focus Measurement)

Wafer coarse focus measurement is performed as follows.

(6) As described in [Outline of Arrangement and Operation of CoarseAlignment Unit], the coarse alignment unit 110 measures the height ofthe upper surface of the wafer at each position in the X and Ydirections. The average focus plane (global focus plane) of the waferwith reference to a chuck reference plane (to be described later) iscalculated from a measurement value of the height and the chuckreference plane. After the wafer is loaded onto the measurement fineadjustment stage 72, the measurement fine adjustment stage is driven inthe height and tilt directions such that the global focus planecoincides with the measurement image plane of the alignment scope 5 of ameasurement unit and the measurement height of a focus measurement unit(focus detection system) 6. This can narrow the measurement range of thefocus measurement unit and can increase the focus measurement precision.Additionally, this can minimize a correction driving amount after themeasurement and can minimize driving errors. In alignment measurement aswell, this can minimize focus shifts generated upon wafer movement andcan increase the alignment precision.

Such a height measurement value is also used to align the upper surfaceof the wafer on the measurement image plane of the alignment scope inthe wafer prealignment measurement.

(Chuck Coarse Focus Measurement)

Chuck coarse focus measurement is performed as follows.

(7) As described in [Outline of Arrangement and Operation of CoarseAlignment Unit], the coarse alignment unit 110 measures in the heightdirection the upper surfaces of the four chuck reference plates 600 onthe edges of the chuck. After the chuck is loaded onto the measurementfine adjustment stage, the measurement unit of the coarse adjustmentstage measures the heights of three or more chuck reference plates,thereby obtaining the chuck reference plane. The global focus plane ofthe wafer is calculated and aligned with reference to the position ofthe reference plane.

Note that such a height measurement value is also used to align theupper surfaces of the reference marks on the measurement image plane ofthe alignment scope in the reference mark measurement.

[Outline of Chuck Reference Mark (FIG. 13)]

FIG. 13 shows a chuck reference mark.

In FIG. 13, reference numeral 500 denotes the chuck; 600, the chuckreference plates arranged at predetermined positions at four corners ofthe chuck 500; 601, measurement areas for electrostatic capacitancesensors which measure the heights of the chuck reference plates; and602, chuck reference marks located on the chuck reference plates.

In the exposure apparatus of this embodiment, the chuck reference platesare arranged at the four corners of the chuck 500, as shown in FIG. 13.Each chuck reference plate is made of quartz and has the measurementarea 601 for the electrostatic capacitance sensor on its surface. Themeasurement area 601 is a conductive pattern and is connected to aground position in the exposure apparatus such that the electrostaticcapacitance sensor can perform high-precision and high-stabilitymeasurement. The position of the upper surface of the measurement areais used as a reference of the height of the chuck. The height ismeasured by a plurality of electrostatic capacitance sensors attached tothe lower surface of the projection system at an exposure position andthe lower surface of the alignment scope of the measurement unit at ameasurement position.

[Outline of Exposure and Focus/Alignment Operations (FIG. 14)]

As one of the characteristic features of the exposure apparatus of thisembodiment, exposure and measurement operations are performed inparallel on two fine adjustment stages on one coarse adjustment stage.

Operation on the coarse adjustment stage will be described below.

FIG. 14 shows the outline of focus/alignment operations; FIG. 15, theoutline of chuck reference mark measurement operation; FIG. 16A, thefocus measurement region of a chuck reference mark on the exposure side;and FIG. 16B, the focus measurement region of a chuck reference mark onthe measurement side.

In FIG. 14, reference numeral 60 denotes the exposure wafer on theexposure chuck 61; 70, the measurement wafer on the measurement chuck71; 610, alignment shots which need alignment measurement; 611, analignment mark for fine alignment measurement located near the alignmentshot 610; 620, an exposure path of the exposure wafer 60; and 630, ameasurement path of the measurement wafer 70. In FIG. 15, referencenumeral 650 denotes an alignment scope which can simultaneously measurea reticle and chuck reference marks; 651, an objective lens of thealignment scope 650; 652, a low-magnification measurement expander ofthe alignment scope 650; 653, a low-magnification measurement CCD cameraof the alignment scope 650; 654, a high-magnification measurement CCDcamera of the alignment scope 650; 5, the alignment scope arranged at anoff-axis position; 660, an objective lens of the alignment scope 5; 661,a low-magnification measurement expander of the alignment scope 5; 662,a low-magnification measurement CCD camera of the alignment scope 5;663, a high-magnification measurement CCD camera of the alignment scope5; 671 to 674, small electrostatic capacitance sensors arranged aroundthe image plane of the projection system 4 to measure the positions ofthe upper surfaces of the corresponding chuck reference plates at anexposure position; and 675 to 678, small electrostatic capacitancesensors arranged around the measurement position of the alignment scope5 so as to have the same positional relationship as that of theelectrostatic capacitance sensors 671 to 674 to measure the positions ofthe upper surfaces of the corresponding chuck reference plates at ameasurement position.

Note that the measurement image plane of the alignment scope 650 islocated at almost the center of the measurement ranges of theelectrostatic capacitance sensors 671 to 674. The measurement imageplane of the alignment scope 5 is located at almost the center of themeasurement ranges of the electrostatic capacitance sensors 675 to 678.

In FIG. 16A, reference numeral 680 denotes an exposure region size whichindicates the size of an exposure region; and 681 to 684, measurementpoints of electrostatic capacitance sensors S1 to S4 arranged on thelower surface of the projection system 4 at the exposure position.

In FIG. 16B, reference numerals 685 to 688 denote measurement points ofelectrostatic capacitance sensors S5 to S8 arranged on the lower surfaceof the alignment scope 5 at the measurement position. Reference numerals691 to 695 denote measurement points of focus sensors R1 to R5 arrangedon the lower surface of the alignment scope 5 at the measurementposition.

FIG. 15 shows only one focus detection system 6 and only one focusdetection system 7. In practice, five detection systems 6 and fivedetection systems 7 are provided in a direction perpendicular to thesheet surface of FIG. 15. The measurement points 691 to 695 of the focussensors R1 to R5 correspond to detection positions of these detectionsystems.

(Outline of Operation)

(1) First Reference Mark Measurement at Measurement Position

In the semiconductor exposure apparatus of this embodiment, when themeasurement chuck 71 is mounted on the measurement fine adjustment stage72 on the coarse adjustment stage 73, the coarse adjustment stage 73 isdriven in the X and Y directions. This driving is performed such thatthe chuck reference mark 602 of the upper right chuck reference plateout of the chuck reference plates 600 on the exposure chuck 61 and thechuck reference mark 602 on the upper right chuck reference plate out ofthe chuck reference plates 600 on the measurement chuck 71simultaneously fall within the measurement areas of the alignment scope650 and alignment scope 5, respectively.

At this time, as for the heights of the reference plates at the fourcorners of the measurement chuck 71, the reference plane for thereference plates is calculated from the measurement results of thereference plates at the four corners by the coarse alignment unit. Themeasurement fine adjustment stage 72 drives the measurement chuck 71 inthe height and tilt directions before the reference mark positionmeasurement such that the reference plane coincides with the measurementimage plane of the alignment scope 5.

The electrostatic capacitance sensors S5 to S8 precisely measure inadvance the heights of the reference plates of the exposure chuck 61while the chuck is on the measurement fine adjustment stage 72. Hence,the exposure fine adjustment stage 62 drives the exposure chuck 61 inthe height and tilt directions on the basis of the measurement resultbefore the reference mark position measurement such that the uppersurfaces of the reference plates coincide with the measurement imageplane of the alignment scope 650.

With the above-mentioned operation, the observation plane of eachreference plane is located at the measurement image plane of thecorresponding alignment scope.

After that, at the measurement position, the electrostatic capacitancesensors S5 to S8 arranged around the measurement image plane of thealignment scope 5 perform precise height measurement of the referenceplates and perform correction driving in the height direction for themeasurement fine adjustment stage such that the upper surfaces of thereference plates accurately coincide with the measurement image plane ofthe alignment scope 5. Then, the alignment scope 5 precisely measuresthe reference marks.

At the exposure position, in parallel with the above-mentionedoperation, the electrostatic capacitance sensors S1 to S4 arrangedaround the measurement image plane of the alignment scope 650 performprecise height measurement of the reference plates and performcorrection driving in the height direction for the exposure fineadjustment stage such that the upper surfaces of the reference platesaccurately coincide with the measurement image plane of the alignmentscope 650. Then, the alignment scope 650 precisely measures thereference marks.

The alignment scopes 5 and 650 perform position measurement using inputimages from the high-magnification measurement CCD cameras 663 and 654and, at the same time, perform measurement using the low-magnificationmeasurement CCD cameras 662 and 653. If each reference mark fallsoutside a high-magnification measurement range, the coarse adjustmentstage 73 and the exposure fine adjustment stage 62 or measurement fineadjustment stage 72 is driven such that the reference mark falls withinthe high-magnification measurement range.

(2) Second Reference Mark Measurement at Measurement Position

The coarse adjustment stage is driven such that the chuck reference mark602 of the lower right chuck reference plate out of the chuck referenceplates 600 on the exposure chuck 61 and the chuck reference mark 602 onthe lower right chuck reference plate out of the chuck reference plates600 on the measurement chuck 71 simultaneously fall within themeasurement areas of the alignment scope 650 and alignment scope 5,respectively. Then, measurement similar to (1) is performed.

(3) Third Reference Mark Measurement at Measurement Position

The coarse adjustment stage is driven such that the chuck reference mark602 of the lower left chuck reference plate out of the chuck referenceplates 600 on the exposure chuck 61 and the chuck reference mark 602 onthe lower left chuck reference plate out of the chuck reference plates600 on the measurement chuck 71 simultaneously fall within themeasurement areas of the alignment scope 650 and alignment scope 5,respectively. Then, measurement similar to (1) and (2) is performed.

After the above-mentioned operation, at the measurement position, theprecise X and Y positions of each chuck reference mark 602 of themeasurement chuck 71 and the reference plane for the reference mark arecalculated while at the exposure position, the precise X and Y positionsof each chuck reference mark 602 of the exposure chuck 61 and thereference plane for the reference mark are calculated.

(4) Exposure and Focus Measurement

With the above-mentioned operation, precise position measurement iscompleted for the chuck reference marks of the measurement chuck 71 andexposure chuck 61. As indicated by the exposure path 620 of FIG. 14,operation of the coarse adjustment stage causes the exposure chuck 61 tostart exposure operation.

In the exposure operation, various correction operations are performedusing results of focus and alignment measurements obtained in advance bythe measurement unit. A detailed description will be given after thechuck of the measurement unit is moved to the exposure unit.

In parallel with the exposure operation of the exposure chuck 61, themeasurement side performs focus measurement of a measurement shot of thewafer on the measurement chuck 71, which is located at the same positionof an exposure shot on the wafer on the exposure chuck 61. At this time,since the height of the wafer on the measurement chuck 71 is obtained inadvance from the measurement result by the coarse focus sensor unit, theglobal focus plane of the wafer is calculated. The measurement fineadjustment stage 72 drives the measurement chuck 71 in the height andtilt directions such that the global focus plane coincides with themeasurement position of the focus detection system 7 before the focusmeasurement. This allows high-precision focus measurement of the entirewafer.

Before the focus measurement, the measurement fine adjustment stage 72is also driven such that the position of a specific pattern of the waferon the measurement chuck 71 and that of a specific pattern of the waferon the exposure chuck 61 have a predetermined positional relationship.

This operation is required to always set focus measurement points on thewafer at predetermined positions and attain high-precision focusmeasurement. This operation is also required to align the alignment mark611 within the measurement region in high-magnification measurement bythe alignment scope 5 at the time of alignment measurement duringexposure (to be described later) and perform precise positionmeasurement.

This operation is performed by calculating the target driving positionof the measurement fine adjustment stage 72 from the measurement resultsof the positions of the chuck reference marks and the prealignment marksin the wafer obtained in advance by the coarse alignment unit 110 andthe measurement results of the chuck reference mark positions describedin (1) to (3).

(5) Exposure and Alignment Measurement

As described above, exposure for the wafer on the exposure chuck 61 andfocus measurement for the wafer on the measurement chuck 71 areperformed in parallel. When each alignment shot 610 comes to near aposition where the focus measurement is performed, scan exposureoperation is temporarily stopped. High-magnification measurement of thealignment scope 5 performs precise position measurement for thealignment mark 611 of the alignment shot 610.

The coarse adjustment stage 73 is temporarily stopped for the alignmentmeasurement. The semiconductor exposure apparatus of this embodimentfollows the measurement path 630 shown in FIG. 14, i.e., switchbacks inthe Y direction and needs to stop temporarily.

The semiconductor exposure apparatus of this embodiment temporarilystops in the X direction in the temporary stop operation in the Ydirection and performs precise position measurement of the wafer on themeasurement chuck 71. The semiconductor exposure apparatus can minimizethe time necessary for alignment measurement operation.

In FIG. 14, alignment measurement is performed for a measurement shotnot having undergone focus measurement. When a measurement shot havingundergone focus measurement comes to near the measurement positionduring exposure operation, the same operation may be performed.

In this case, use of focus measurement data for each shot enables notfocus alignment of only the global focus plane but more accurate focusalignment for alignment shots, thereby allowing more precise alignmentmeasurement.

(6) Last Reference Mark Measurement

Upon completion of exposure of the wafer on the exposure chuck 61 andfocus and alignment measurements of the wafer on the measurement chuck71, the coarse adjustment stage operates to move the chuck referencemarks on the exposure chuck 61 and the chuck reference marks on themeasurement chuck 71 below the alignment scopes 650 and 5.High-magnification measurement of each alignment scope confirms whetherthe exposure and measurement operations cause any positional shift ofeach chuck. If the measurement result detects a shift amount of apredetermined tolerance or more, each chuck is recovered to the loadingplate 120. In this state, nitrogen for cleaning is ejected from eachfine adjustment stage to perform cleaning.

When the positional shift amount approaches the predetermined tolerance,a warning is issued. If the positional shift amount is too large tocorrect by the cleaning, the apparatus stops abnormally.

(7) Movement from Measurement Fine Adjustment Stage to Exposure FineAdjustment Stage

When all the measurements at the measurement position are completed, thecoarse adjustment stage moves to the right rear. The loading plate 120moves to the coarse adjustment stage side (right side) and reaches theupper portion of the right half of the coarse adjustment stage. The twofine adjustment stages on the coarse adjustment stage 73 are moved at anormal height to the left rear and are fit into the loading plate 120.

At this position, each fine adjustment stage turns off the Vac. of thecorresponding chuck and moves downward, thereby moving the chuck ontothe loading plate 120. Then, the coarse adjustment stage 73 is moved tothe left front, and at this position, each fine adjustment stage ismoved upward. With this operation, unloading of a chuck holding a waferhaving undergone exposure, movement of a chuck holding a wafer havingundergone measurement from the measurement fine adjustment stage 72 tothe exposure fine adjustment stage 62, and loading of a chuck holding awafer to be measured next onto the measurement fine adjustment stage 72are performed.

A detailed description will be given in [Outline of Operation of WaferStage Unit (FIGS. 17 to 20)].

(8) First Reference Mark Measurement at Exposure Position

Operation at the exposure position described in “(1) First ReferenceMark Measurement at Measure Position” is performed.

(9) Second Reference Mark Measurement at Exposure Position

Operation at the exposure position described in “(2) Second ReferenceMark Measurement at Measure Position” is performed.

(10) Third Reference Mark Measurement at Exposure Position

Operation at the exposure position described in “(3) Third ReferenceMark Measurement at Measure Position” is performed.

(11) Exposure

An explanation of various correction operations in exposure is omittedfrom “(4) Exposure and Focus Measurement” and will be given below.

The positions of the upper surface of the wafer to be exposed at the Xand Y positions and the positions of the alignment marks of thealignment shots on the wafer with reference to the chuck reference marksare obtained from the measurement results obtained in (1) to (5).

When each of the positions of the upper surface of the wafer at the Xand Y positions comes to the exposure position, the exposure fineadjustment stage 62 drives the wafer such that the position accuratelycoincides with the exposure image plane of the projection system 4.

The measurement result of the position of each alignment mark isdecomposed after the measurement into wafer position errors in the X, Y,and θ directions, a wafer magnification error, an X-Y arrayorthogonality error, and the like. These errors are corrected by thecoarse adjustment stage 73 in exposure, the position of the exposurefine adjustment stage 62, the scan rates of the reticle and wafer,magnification correction of the projection system, and the like.

[Outline of Operation of Wafer Stage Unit (FIGS. 17 to 20)]

The semiconductor exposure apparatus of this embodiment performsexposure and measurement operations in parallel on one coarse adjustmentstage. This parallel operation will be described below in detail.

FIGS. 17 to 19 show the outline of operation of a wafer stage. In FIGS.17 to 19, reference symbols A and B denote empty chucks, and a chuck onwhich a wafer is mounted bears the number of the wafer.

Note that a chuck holding wafer No. 1 will be referred to as chuck No. 1hereinafter. FIG. 20 is the operation flow of FIGS. 17 to 19. Thecircled process numbers are the same as those shown in FIGS. 17 to 19.

(Outline of Operation)

The sequence from the beginning to the end of the wafer process of thesemiconductor exposure apparatus according to this embodiment is mainlydivided into the following six blocks in the case of N wafers.

-   (1) Measurement of First Wafer-   (2) (Measurement of Second Wafer) & (Exposure of First Wafer)-   (3) (Measurement of Third to (N-1)th Wafers) & (Exposure of Second    to (N-2)th Wafers)-   (4) (Measurement of Nth Wafer) & (Exposure of (N-1)th Wafer)-   (5) Exposure of Nth Wafer-   (6) End Process

These blocks will be explained below in detail.

(1) Measurement of First Wafer

No. 1: Movement of First Wafer onto Loading Plate

The semiconductor exposure apparatus of this embodiment incorporatesthree chucks, which stand by at the following positions in their initialstates.

At the wafer loading position on the coarse alignment unit 110

On the exposure fine adjustment stage 62

On the measurement fine adjustment stage 72

Upon completion of coarse alignment in the coarse alignment unit 110,the first wafer is loaded at the chuck loading position 121 on theloading plate 120 by the chuck hand 123, as shown in FIG. 17. Note thatthe chuck hand 123 retreats and stands by at the rearmost position.

No. 2: Insertion of Loading Plate

The loading plate 120 is inserted into the coarse adjustment stage 73.The coarse adjustment stage moves to the unloading position (left rear)while the exposure fine adjustment stage 62 and measurement fineadjustment stage 72 are kept elevated, and the fine adjustment stagesmove downward. With this operation, the empty chucks A and B move ontothe loading plate 120.

No. 3: Movement of Coarse Adjustment Stage to Loading Position

After the empty chucks A and B are passed to the loading plate 120, thecoarse adjustment stage 73 moves from the unloading position (left rear)to the loading position (left front). At this position, the exposurefine adjustment stage 62 and measurement fine adjustment stage 72 moveupward. The empty chuck B is coupled to the exposure fine adjustmentstage 62 while chuck No. 1 holding the first process wafer is coupled tothe measurement fine adjustment stage 72.

No. 4: Retreat of Loading Plate

The loading plate 120 externally retreats from the coarse adjustmentstage 73, and movement of the empty chuck B and chuck No. 1 to thecoarse adjustment stage 73 completes. The empty chuck A on the loadingplate 120 is unloaded by the chuck hand 123 to the coarse alignment unit110.

No. 5: Reference Mark Measurement (On Measurement Side)

The electrostatic capacitance sensors S5 to S8 on the measurement sidemeasure the upper surfaces of the chuck reference plates on chuck No. 1,and at the same time, the focus detection system 7 performs focusmeasurement. The electrostatic capacitance sensors S5 to S8 and focusdetection system 7 perform calibration. The alignment scope(simultaneous measurement at low and high magnifications) on themeasurement side measures the chuck reference marks 602 in the chuckreference plates 600 on chuck No. 1.

Though not shown, the two or more chuck reference marks 602 aremeasured.

No. 6: Focus Measurement

The coarse adjustment stage 73 is driven in the same manner as in actualexposure, and the focus detection system 7 on the measurement sideperforms focus measurement for the entire upper surface of chuck No. 1.

If an alignment shot comes to near a position where focus measurement isbeing performed by the alignment scope 5 (high-magnification) on themeasurement side, alignment measurement is also performed, as shown inFIG. 14.

During this operation, chuck No. 2 is moved to the chuck loadingposition 121 of the loading plate 120, as shown in FIG. 17.

No. 7: Reference Mark Measurement (On Measurement Side)

After the measurement, the alignment scope 5 (high-magnification) on themeasurement side measures the chuck reference marks 602 in the chuckreference plates 600 on chuck No. 1.

It is confirmed whether the measurement operation causes any positionalshift of the chuck.

(2) (Measurement of Second Wafer) & (Exposure of First Wafer)

No. 8: Insertion of Loading Plate

The loading plate 120 is inserted. Then, the coarse adjustment stage 73moves to the unloading position (left rear) while the exposure fineadjustment stage 62 and measurement fine adjustment stage 72 are keptelevated, and the fine adjustment stages move downward. With thisoperation, the empty chuck B and chuck No. 1 are moved onto the loadingplate 120.

No. 9: Movement of Coarse Adjustment Stage to Loading Position

After the empty chuck B and chuck No. 1 are passed to the loading plate120, the coarse adjustment stage 73 moves from the unloading position(left rear) to the loading position (left front).

At this position, the exposure fine adjustment stage 62 and measurementfine adjustment stage 72 move upward. Chuck No. 1 is coupled to theexposure fine adjustment stage 62 while chuck No. 2 holding the secondprocess wafer is coupled to the measurement fine adjustment stage 72.

No. 10: Retreat of Loading Plate

The loading plate 120 externally retreats from the coarse adjustmentstage 73, and movement of chuck Nos. 1 and 2 to the coarse adjustmentstage 73 completes. The empty chuck B on the loading plate 120 isunloaded by the chuck hand 123 to the coarse alignment unit 110.

No. 11: Reference Mark Measurement (Two Chucks)

On the measurement side, the measurement electrostatic capacitancesensors S5 to S8 measure the upper surfaces of the chuck referenceplates on chuck No. 2.

At the same time, the focus detection system 7 performs focusmeasurement. The electrostatic capacitance sensors S5 to S8 and focusdetection system 7 perform calibration. The alignment scope 5(simultaneous measurement at low and high magnifications) on themeasurement side measures the chuck reference marks 602 in the chuckreference plates 600 on chuck No. 2.

Though not shown, the two or more chuck reference marks 602 aremeasured.

On the exposure side, the exposure electrostatic capacitance sensors S1to S4 measure the upper surfaces of the chuck reference plates on chuckNo. 1 in parallel with the above-mentioned operation.

The alignment scope (simultaneous measurement at low and highmagnifications) on the exposure side measures the chuck reference marks602 in the chuck reference plates 600 on chuck No. 1 to calculateinformation required for exposure.

No. 12: Focus Measurement and Exposure

The exposure unit starts exposure operation for wafer No. 1.

In parallel with this, the focus detection system 7 on the measurementside performs focus measurement for the entire upper surface of chuckNo. 2.

If an alignment shot comes to near a position where focus measurement isbeing performed by the alignment scope 5 (high-magnification) on themeasurement side, alignment measurement is also performed for wafer No.2, as shown in FIG. 14.

During this operation, chuck No. 3 is moved to the chuck loadingposition 121 of the loading plate 120, as shown in FIG. 17.

No. 13: Reference Mark Measurement (Two Chucks)

After the measurement, the alignment scopes (high-magnification) on theexposure and measurement sides measure the chuck reference marks 602 inthe chuck reference plates 600 on chuck Nos. 1 and 2.

It is confirmed whether the exposure and measurement operations causeany positional shift of the chucks.

(3) (Measurement of Third to (N-1)th Wafers) & (Exposure of Second to(N-2)th Wafers)

No. 14: Insertion of Loading Plate

The loading plate 120 is inserted. Then, the coarse adjustment stage 73moves to the unloading position (left rear) while the exposure fineadjustment stage 62 and measurement fine adjustment stage 72 are keptelevated, and the fine adjustment stages move downward. With thisoperation, chuck Nos. 1 and 2 are moved onto the loading plate 120.

No. 15: Movement of Coarse Adjustment Stage to Loading Position

After chuck Nos. 1 and 2 are passed to the loading plate 120, the coarseadjustment stage 73 moves from the unloading position (left rear) to theloading position (left front).

At this position, the exposure fine adjustment stage 62 and measurementfine adjustment stage 72 move upward. Chuck No. 2 is coupled to theexposure fine adjustment stage 62 while chuck No. 3 holding the thirdprocess wafer is coupled to the measurement fine adjustment stage 72.

No. 16: Retreat of Loading Plate

The loading plate 120 externally retreats from the coarse adjustmentstage 73, and movement of chuck Nos. 2 and 3 to the coarse adjustmentstage 73 completes.

Chuck No. 1 having undergone exposure on the loading plate 120 isunloaded by the chuck hand 123 to the coarse alignment unit 110.

No. 17: Reference Mark Measurement (Two Chucks)

Reference mark measurement similar to that in No. 11 is performed forchuck Nos. 3 and 2.

No. 18: Focus Measurement and Exposure

Focus measurement and exposure similar to that in No. 12 is performedfor chuck Nos. 3 and 2.

During this operation, chuck No. 4 is moved to the chuck loadingposition 121 of the loading plate 120, as shown in FIG. 18.

No. 19: Reference Mark Measurement (Two Chucks)

Reference mark measurement similar to that in No. 13 is performed forchuck Nos. 3 and 2.

The above-mentioned operation is repeated until chuck No. N holding thelast process wafer is loaded onto the loading plate. The processes tofollow are obtained by incrementing the chuck number in Nos. 14 to 19 byone.

(4) (Measurement of Nth Wafer) & (Exposure of (N-1)th Wafer)

No. 20: Insertion of Loading Plate

Chuck Nos. (N-2) and (N-1) are moved onto the loading plate 120.Basically, operation similar to that in No. 14 is performed.

No. 21: Movement of Coarse Adjustment Stage to Loading Position

After chuck Nos. (N-2) and (N-1) are passed to the loading plate 120,the coarse adjustment stage 73 moves from the unloading position (leftrear) to the loading position (left front).

At this position, the exposure fine adjustment stage 62 and measurementfine adjustment stage 72 move upward. Chuck No. (N-1) is coupled to theexposure fine adjustment stage 62 while chuck No. N holding the lastprocess wafer is coupled to the measurement fine adjustment stage 72.

No. 22: Retreat of Loading Plate

The loading plate 120 externally retreats from the coarse adjustmentstage 73, and the exposure fine adjustment stage 62 and measurement fineadjustment stage 72 move downward. Movement of chuck Nos. (N-1) and N tothe coarse adjustment stage 73 completes.

Chuck No. (N-2) having undergone exposure on the loading plate 120 isunloaded by the chuck hand 123 to the coarse alignment unit 110.

No. 23: Reference Mark Measurement (Two Chucks)

Reference mark measurement similar to that in No. 11 is performed forchuck Nos. N and (N-1).

No. 24: Focus Measurement and Exposure

Focus measurement and exposure similar to that in No. 12 is performedfor chuck Nos. N and (N-1).

During this operation, the empty chuck A is moved to the chuck loadingposition 121 of the loading plate 120, as shown in FIG. 18.

No. 25: Reference Mark Measurement (Two Chucks)

Reference mark measurement similar to that in No. 13 is performed forchuck Nos. N and (N-1).

(5) Exposure of Nth Wafer

No. 26: Insertion of Loading Plate

Chuck Nos. (N-1) and N are moved onto the loading plate 120. Basically,operation similar to that in No. 14 is performed.

No. 27: Movement of Coarse Adjustment Stage to Loading Position

After chuck Nos. (N-1) and N are passed to the loading plate 120, thecoarse adjustment stage 73 moves from the unloading position (left rear)to the loading position (left front).

At this position, the exposure fine adjustment stage 62 and measurementfine adjustment stage 72 move upward. Chuck No. N is coupled to theexposure fine adjustment stage 62 while the empty chuck A is coupled tothe measurement fine adjustment stage 72.

No. 28: Retreat of Loading Plate

The loading plate 120 retreats, and the exposure fine adjustment stage62 and measurement fine adjustment stage 72 move downward. Movement ofchuck No. N and empty chuck A to the coarse adjustment stage 73completes.

Chuck No. (N-1) having undergone exposure on the loading plate 120 isunloaded by the chuck hand 123 to the coarse alignment unit 110.

No. 29: Reference Mark Measurement (On Exposure Side)

The measurement side bearing the empty chuck does not performmeasurement. Only measurement of the chuck reference marks 602 in thechuck reference plates 600 on chuck No. N is performed by the alignmentscope 650.

No. 30: Exposure

Exposure of chuck No. N starts. The measurement side bearing the emptychuck does not perform focus measurement and the like.

During this operation, the empty chuck B is moved to the chuck loadingposition 121 of the loading plate 120, as shown in FIG. 19.

(6) End Process

No. 31: Insertion of Loading Plate

Chuck No. N and the empty chuck A are moved onto the loading plate 120.

No. 32: Movement of Coarse Adjustment Stage to Loading Position

After chuck No. N and the empty chuck A are passed to the loading plate120, the coarse adjustment stage 73 moves from the unloading position(left rear) to the loading position (left front).

At this position, the exposure fine adjustment stage 62 and measurementfine adjustment stage 72 move upward. The empty chuck A is coupled tothe exposure fine adjustment stage 62 while the empty chuck B is coupledto the measurement fine adjustment stage 72.

No. 33: Retreat of Loading Plate

The loading plate 120 retreats, and the exposure fine adjustment stage62 and measurement fine adjustment stage 72 move downward. Movement ofthe empty chucks A and B to the coarse adjustment stage 73 completes.

Chuck No. N having undergone the last exposure on the loading plate 120is unloaded by the chuck hand 123 to the coarse alignment unit 110.

No. 34: Movement of Coarse Adjustment Stage to Unloading Position

The coarse adjustment stage 73 is moved to the unloading position, andthe entire wafer process ends.

Operation that pertains to the coarse adjustment stage has beendescribed. In the semiconductor exposure apparatus of this embodiment,both the exposure fine adjustment stage 62 and the measurement fineadjustment stage 72 on the coarse adjustment stage 73 have respectivechucks. The coarse adjustment stage is driven only when the chucks arenot mounted on the fine adjustment stages. This aims at keeping theweight balance of the coarse adjustment stage constant and maintainingthe stable stage performance in high-speed driving.

[Outline of Chuck Unloading Function (FIG. 21)]

FIG. 21 shows how a chuck is unloaded. In FIG. 21, reference numeral 700denotes a chuck cassette which can accommodate a plurality of chucks.

The semiconductor exposure apparatus of this embodiment inserts the handunit of the unloading hand 131 into the chuck support unit 412 below thechuck 405 and unload the chuck 405 from the coarse chuck stage 113 tothe unloading load-lock chamber 130 at the wafer unloading position ofthe coarse alignment unit 110.

The chuck 405 having been unloaded to the unloading load-lock chamber130 is accommodated by the wafer hand 102 in the chuck cassette 700,similarly to a wafer.

FIG. 21 shows an unloading operation. A chuck loading operation can beperformed in a reverse order to that shown in FIG. 21.

[Modification]

As modifications of the semiconductor exposure apparatus according tothe embodiment of the present invention, the following semiconductorexposure apparatuses can readily be devised:

1. a semiconductor exposure apparatus which uses two chucks;

2. a semiconductor exposure apparatus which uses four or more chucks,further divides each process in transport and prealignment units intosmaller processes, and performs the processes in parallel;

3. a semiconductor exposure apparatus which uses a hand to move a chuckfrom a loading position to the first stage, to move from the first stageto the second stage, and to move from the second stage to an unloadingposition;

4. a semiconductor exposure apparatus which measures the height of chuckreference plates and that of a wafer by the same sensor; and

5. a semiconductor exposure apparatus in which each measurement fineadjustment stage is fixed to perform measurements whose measurementranges are wide by focus measurement and alignment systems.

In this case, each measurement system needs to increase the measurementrange while maintaining the measurement precision. On the other hand, nointerference occurs between two fine adjustment stages due tovibrations.

As has been described above, according to this embodiment, for example,two fine adjustment stages are arranged on one coarse adjustment stage,and part of exposure, focus measurement, and alignment measurement canbe performed simultaneously at exposure and measurement positions byoperation of the one coarse adjustment stage. This makes it possible toimplement a small high-speed exposure apparatus.

A wafer having undergone measurement on the measurement fine adjustmentstage on the one coarse adjustment stage only needs to move onto theadjacent exposure fine adjustment stage. This prevents any positionalshift of the wafer after the measurement from a chuck and implementsmore accurate alignment/focus at the exposure position.

Since a large focus detection system for wafer measurement is spacedapart from below a projection system, this embodiment can produceadditional effects. More specifically, constraints on mounting space arerelaxed for the focus detection system for wafer measurement. This makesit much easier to improve and maintain the focus detection system forwafer measurement.

In addition, since the focus measurement system need not be arrangedbelow the projection system, constraints on the design of the projectionsystem are relaxed.

A chuck unloading mechanism according to this embodiment can easily andautomatically unload or load the chuck to or from the outer air sideeven when its exposure space is purged with nitrogen or evacuated to avacuum. This largely shortens a maintenance time and makes it possibleto maintain the cleanliness of the space.

[Other Embodiment]

The present invention includes a case wherein the invention is achievedby directly or remotely supplying a program of software that implementsa control flow for measurement and exposure operations of theaforementioned embodiment to a system or apparatus, and reading out andexecuting the supplied program code by a computer of that system orapparatus. In this case, software need not have the form of a program aslong as it has the program function.

Therefore, the program code itself installed in a computer to implementthe functional process of the present invention using the computerimplements the present invention. That is, the scope of the claims ofthe present invention includes the computer program itself forimplementing the functional process of the present invention.

In this case, the form of a program is not particularly limited, and anobject code, a program to be executed by an interpreter, script data tobe supplied to an operating system (OS), and the like, may be used aslong as they have the program function.

As a recording medium for supplying the program, for example, a flexibledisk, a hard disk, an optical disk, a magnetooptical disk, an MO, aCD-ROM, a CD-R, a CD-RW, a magnetic tape, a nonvolatile memory card, aROM, a DVD (DVD-ROM, DVD-R), and the like, may be used.

As another program supply method, the program may be supplied byestablishing connection to a home page on the Internet using a browseron a client computer, and downloading the computer program itself of thepresent invention or a compressed file containing an automaticinstallation function from the home page onto a recording medium such asa hard disk or the like. Also, the program code that forms the programof the present invention may be segmented into a plurality of files,which may be downloaded from different home pages. That is, the scope ofthe claims of the present invention includes a World Wide Web (WWW)server, which makes a plurality of users download a program filerequired to implement the functional process of the present invention bythe computer.

Also, a storage medium such as a CD-ROM or the like, which stores theencrypted program of the present invention, may be delivered to theuser, the user who has cleared a predetermined condition may be allowedto download key information that decrypts the program from a home pagevia the Internet, and the encrypted program may be executed using thatkey information to be installed on a computer, thus implementing thepresent invention.

The functions of the aforementioned embodiment may be implemented notonly by executing the program code read out by the computer, but also bysome of or all of actual processing operations executed by an OS, or thelike, running on the computer, on the basis of an instruction of thatprogram.

Furthermore, the functions of the aforementioned embodiment may beimplemented by some or all of actual processes executed on the basis ofan instruction of that program by a CPU or the like arranged in afunction extension board or a function extension unit, which is insertedin or connected to the computer, after the program read out from therecording medium is written in a memory of the extension board or unit.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

1. An exposure apparatus which exposes substrates to a pattern on amaster, said apparatus comprising: first, second, and third chucks whichhold the substrates; a first fine adjustment stage which holds saidfirst chuck to perform fine driving; a second fine adjustment stagewhich holds said second chuck to perform fine driving; a coarseadjustment stage on which said first and second fine adjustment stagesare mounted and which can move in an X Y plane substantiallyperpendicular to an optical axis; an exposure unit which performs anexposure operation for the substrate held by said first chuck; ameasurement unit which performs a measurement operation for thesubstrate held by said second chuck; and a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck, wherein said first chuck also serves as said third chuck.
 2. Theapparatus according to claim 1, further comprising a chuck in additionto said first to third chucks.
 3. The apparatus according to claim 1,wherein the master and substrates are brought into a stationary stateduring the exposure operation.
 4. The apparatus according to claim 1,wherein the master and substrates are scanned during the exposureoperation.
 5. An exposure apparatus which exposes substrates to apattern on a master, said apparatus comprising: first, second, and thirdchucks which hold the substrates; a first fine adjustment stage whichholds said first chuck to perform fine driving; a second fine adjustmentstage which holds said second chuck to perform fine driving; a coarseadjustment stage on which said first and second fine adjustment stagesare mounted and which can move in an X Y plane substantiallyperpendicular to an optical axis; an exposure unit which performs anexposure operation for the substrate held by said first chuck; ameasurement unit which performs a measurement operation for thesubstrate held by said second chuck; a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck; and a chuck holding mechanism which temporarily holds said firstand second chucks outside said coarse adjustment stage, whereinunloading of said first chuck from said first fine adjustment stage andmovement of said second chuck from said second fine adjustment stage tosaid first fine adjustment stage are performed in parallel bytemporarily moving said first chuck which holds the substrate havingundergone the exposure operation and said second chuck which holds thesubstrate having undergone the measurement operation from said coarseadjustment stage to said chuck holding mechanism, moving said coarseadjustment stage separated from said first and second chucks, andreturning said second chuck to said coarse adjustment stage.
 6. Theapparatus according to claim 5, further comprising a chuck in additionto said first to third chucks.
 7. The apparatus according to claim 5,wherein the master and substrates are brought into a stationary stateduring the exposure operation.
 8. The apparatus according to claim 5,wherein the master and substrates are scanned during the exposureoperation.
 9. An exposure apparatus which exposes substrates to apattern on a master, said apparatus comprising: first, second, and thirdchucks which hold the substrates; a first fine adjustment stage whichholds said first chuck to perform fine driving; a second fine adjustmentstage which holds said second chuck to perform fine driving; a coarseadjustment stage on which said first and second fine adjustment stagesare mounted and which can move in an X Y plane substantiallyperpendicular to an optical axis; an exposure unit which performs anexposure operation for the substrate held by said first chuck; ameasurement unit which performs a measurement operation for thesubstrate held by said second chuck; a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck; and a chuck holding mechanism which temporarily holds said first,second, and third chucks outside said coarse adjustment stage, whereinunloading of said first chuck from said first fine adjustment stage,movement of said second chuck from said second fine adjustment stage tosaid first fine adjustment stage, and loading of said third chuck tosaid second fine adjustment stage are performed in parallel bytemporarily moving said first chuck which holds the substrate havingundergone the exposure operation and said second chuck which holds thesubstrate having undergone the measurement operation from said coarseadjustment stage to said chuck holding mechanism, moving said coarseadjustment stage separated from said first and second chucks, andreturning said second and third chucks to said coarse adjustment stage.10. The apparatus according to claim 9, further comprising a chuck inaddition to said first to third chucks.
 11. The apparatus according toclaim 9, wherein the master and substrates are brought into a stationarystate during the exposure operation.
 12. The apparatus according toclaim 9, wherein the master and substrates are scanned during theexposure operation.
 13. An exposure apparatus which exposes substratesto a pattern on a master, said apparatus comprising: first, second, andthird chucks which hold the substrates; a first fine adjustment stagewhich holds said first chuck to perform fine driving; a second fineadjustment stage which holds said second chuck to perform fine driving;a coarse adjustment stage on which said first and second fine adjustmentstages are mounted and which can move in an X Y plane substantiallyperpendicular to an optical axis; an exposure unit which performs anexposure operation for the substrate held by said first chuck; ameasurement unit which performs a measurement operation for thesubstrate held by said second chuck; and a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck, wherein at least one reference plane for a height direction isarranged on an edge of each of said chucks which hold the substrates, afirst sensor which measures the reference plane in the height directionis arranged below a projection system of said exposure unit, a secondsensor which measures the reference plane in the height direction and athird sensor which measures the substrate in the height direction arearranged below said measurement unit, said measurement unit measures aheight of the reference plane by the second sensor and measures a heightat each position in the X Y plane of the substrate by the third sensor,and said exposure unit measures the reference plane in the heightdirection by the first sensor, then calculates each position in the X Yplane of the substrate from measurement results of the height of thereference plane and the height at each position in the X Y plane of thesubstrate obtained in advance by the second and third sensors in saidmeasurement unit and a measurement result by the first sensor, andperforms the exposure operation by driving in the height direction orthe height direction and a tilt direction of the substrate such thateach exposure region on the substrate coincides with a position of animage plane of the projection system.
 14. The apparatus according toclaim 13, wherein measurement of the height at each position in the X Yplane of the substrate by the third sensor in said measurement unit, andexposure operation for the substrate having undergone measurement insaid exposure unit are performed in parallel.
 15. The apparatusaccording to claim 13, wherein measurement of a reference plane on saidfirst chuck by the first sensor and measurement of a reference plane onsaid second chuck by the second sensor are performed in parallel. 16.The apparatus according to claim 13, wherein calibration of the secondand third sensors is executed by simultaneously performing measurementof a reference plane on said second chuck by the second sensor andmeasurement of the reference plane on said second chuck by the thirdsensor.
 17. The apparatus according to claim 13, wherein the secondsensor measures the reference plane and the substrate in the heightdirection, and the third sensor can be removed.
 18. The apparatusaccording to claim 13, wherein the first and second sensors are of thesame type.
 19. The apparatus according to claim 13, wherein the firstand second sensors are of an electrostatic capacitance type.
 20. Theapparatus according to claim 13, wherein the third sensor comprises aprojection unit which projects a specific mark onto a substrate byoblique incidence and a detection unit which image senses the specificmark.
 21. The apparatus according to claim 13, further comprising achuck in addition to said first to third chucks.
 22. The apparatusaccording to claim 13, wherein the master and substrates are broughtinto a stationary state during the exposure operation.
 23. The apparatusaccording to claim 13, wherein the master and substrates are scannedduring the exposure operation.
 24. An exposure apparatus which exposessubstrates to a pattern on a master, said apparatus comprising: first,second, and third chucks which hold the substrates; a first fineadjustment stage which holds said first chuck to perform fine driving; asecond fine adjustment stage which holds said second chuck to performfine driving; a coarse adjustment stage on which said first and secondfine adjustment stages are mounted and which can move in an X Y planesubstantially perpendicular to an optical axis; an exposure unit whichperforms an exposure operation for the substrate held by said firstchuck; a measurement unit which performs a measurement operation for thesubstrate held by said second chuck; and a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck, wherein at least one reference mark for X and Y directions isarranged on an edge of each of said chucks which hold the substrates, afirst alignment unit which measures the reference mark in the X and Ydirections is arranged in said exposure unit, a second alignment unitwhich measures the reference mark and alignment marks for measurementshots on each substrate in the X and Y directions is arranged in saidmeasurement unit, said measurement unit measures the reference mark inthe X and Y directions and a position of the alignment marks for themeasurement shots in the X and Y directions by the second alignmentunit, and said exposure unit measures the reference mark in the X and Ydirections by the first alignment unit, calculates an alignment error ateach position of the substrate from measurement results of the referencemark and each position in the X and Y directions of the substrateobtained in advance by the second alignment unit in said measurementunit and a measurement result of the reference mark by the firstalignment unit, and performs the exposure operation by correcting theerror such that the substrate is exposed to the pattern on the master ata predetermined position.
 25. The apparatus according to claim 24,wherein the measurement of the position of the alignment marks for themeasurement shots on the substrate by the second alignment unit isperformed in parallel with the exposure operation or by temporarilyinterrupting the exposure operation when the second alignment unit comesto near the measurement shot during the exposure operation for thesubstrate by said exposure unit.
 26. The apparatus according to claim25, wherein said coarse adjustment stage is driven such that a Ydirection speed in a turning operation becomes zero at a Y coordinate ofthe position of the alignment mark for the measurement shot and istemporarily stopped such that an X direction speed becomes zero at an Xcoordinate of the position of the alignment mark for the measurementshot.
 27. The apparatus according to claim 24, wherein the measurementof the reference mark in the X and Y directions on said first chuck bythe first alignment unit and the measurement of the reference mark onsaid second chuck by the second alignment unit are performed inparallel.
 28. The apparatus according to claim 24, wherein the firstalignment unit can perform simultaneous measurement at high and lowmagnifications, performs the simultaneous measurement at the high andlow magnifications for the reference mark on said first chuck, performsposition measurement for the reference mark if the reference mark fallswithin a high magnification measurement range, and performs positionmeasurement for the reference mark by driving said first adjustmentstage or said first adjustment stage and coarse adjustment stage on thebasis of a measurement result of the low magnification to move thereference mark to the high magnification measurement range if thereference mark falls outside the high magnification measurement range.29. The apparatus according to claim 24, wherein the second alignmentunit can perform simultaneous measurement at high and lowmagnifications, performs the simultaneous measurement at the high andlow magnifications for the reference mark on said second chuck, performsposition measurement for the reference mark if the reference mark fallswithin a high magnification measurement range, and performs positionmeasurement for the reference mark by driving said second adjustmentstage or said second adjustment stage and coarse adjustment stage on thebasis of a measurement result of the low magnification to move thereference mark to the high magnification measurement range if thereference mark falls outside the high magnification measurement range.30. The apparatus according to claim 24, further comprising a chuck inaddition to said first to third chucks.
 31. The apparatus according toclaim 24, wherein the master and substrates are brought into astationary state during the exposure operation.
 32. The apparatusaccording to claim 24, wherein the master and substrates are scannedduring the exposure operation.
 33. An exposure apparatus which exposessubstrates to a pattern on a master, said apparatus comprising: first,second, and third chucks which hold the substrates; a first fineadjustment stage which holds said first chuck to perform fine driving; asecond fine adjustment stage which holds said second chuck to performfine driving; a coarse adjustment stage on which said first and secondfine adjustment stages are mounted and which can move in an X Y planesubstantially perpendicular to an optical axis; an exposure unit whichperforms an exposure operation for the substrate held by said firstchuck; a measurement unit which performs a measurement operation for thesubstrate held by said second chuck; and a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck, wherein a position of a chuck reference mark on each of saidchucks and a position of an alignment mark on the substrate held on saidchuck are measured before loading said chuck to said coarse adjustmentstage, and said chuck is loaded to said coarse adjustment stage suchthat the chuck reference mark and said coarse adjustment stage have apredetermined positional relationship.
 34. The apparatus according toclaim 33, further comprising a chuck in addition to said first to thirdchucks.
 35. The apparatus according to claim 33, wherein the master andsubstrates are brought into a stationary state during the exposureoperation.
 36. The apparatus according to claim 33, wherein the masterand substrates are scanned during the exposure operation.
 37. Anexposure apparatus which exposes substrates to a pattern on a master,said apparatus comprising: first, second, and third chucks which holdthe substrates; a first fine adjustment stage which holds said firstchuck to perform fine driving; a second fine adjustment stage whichholds said second chuck to perform fine driving; a coarse adjustmentstage on which said first and second fine adjustment stages are mountedand which can move in an X Y plane substantially perpendicular to anoptical axis; an exposure unit which performs an exposure operation forthe substrate held by said first chuck; a measurement unit whichperforms a measurement operation for the substrate held by said secondchuck; and a controller which drives said coarse adjustment stage andcauses said measurement and exposure units to perform the measurementand exposure operations, respectively, wherein said controller performsin parallel the measurement and exposure operations for the substratesby serially performing: (i) an operation of unloading the substratehaving undergone the exposure operation together with said first chuckfrom said first fine adjustment stage, (ii) an operation of moving thesubstrate having undergone the measurement operation from said secondfine adjustment stage to said first fine adjustment stage while thesubstrate is held by said second chuck, and (iii) an operation ofloading a substrate to be subjected to the measurement operation nextwhile the substrate is held by said third chuck, wherein a position of achuck reference mark on each of said chucks and a position of analignment mark on the substrate held on said chuck are measured beforeloading said chuck to said coarse adjustment stage, and relativealignment of said chuck with the substrate is performed such that thealignment mark and the chuck reference mark have a predeterminedrelative positional relationship.
 38. The apparatus according to claim37, further comprising a chuck in addition to said first to thirdchucks.
 39. The apparatus according to claim 37, wherein the master andsubstrates are brought into a stationary state during the exposureoperation.
 40. The apparatus according to claim 37, wherein the masterand substrates are scanned during the exposure operation.
 41. Anexposure apparatus which exposes substrates to a pattern on a master,said apparatus comprising: first, second, and third chucks which holdthe substrates; a first fine adjustment stage which holds said firstchuck to perform fine driving; a second fine adjustment stage whichholds said second chuck to perform fine driving; a coarse adjustmentstage on which said first and second fine adjustment stages are mountedand which can move in an X Y plane substantially perpendicular to anoptical axis; an exposure unit which performs an exposure operation forthe substrate held by said first chuck; a measurement unit whichperforms a measurement operation for the substrate held by said secondchuck; and a controller which drives said coarse adjustment stage andcauses said measurement and exposure units to perform the measurementand exposure operations, respectively, wherein said controller performsin parallel the measurement and exposure operations for the substratesby serially performing: (i) an operation of unloading the substratehaving undergone the exposure operation together with said first chuckfrom said first fine adjustment stage, (ii) an operation of moving thesubstrate having undergone the measurement operation from said secondfine adjustment stage to said first fine adjustment stage while thesubstrate is held by said second chuck, and (iii) an operation ofloading a substrate to be subjected to the measurement operation nextwhile the substrate is held by said third chuck, wherein a height of achuck reference mark on each of said chucks and heights at a pluralityof positions in X and Y directions of the substrate held on said chuckare measured before loading said chuck to said coarse adjustment stage,and after said chuck is loaded to said second fine adjustment stage,said chuck is driven in height and tilt directions by said second fineadjustment stage on the basis of a measurement result such that theheight of the chuck reference mark and the heights of the substrate fallwithin measurement ranges of the second and third sensors.
 42. Theapparatus according to claim 41, further comprising a chuck in additionto said first to third chucks.
 43. The apparatus according to claim 41,wherein the master and substrates are brought into a stationary stateduring the exposure operation.
 44. The apparatus according to claim 41,wherein the master and substrates are scanned during the exposureoperation.
 45. An exposure apparatus which exposes substrates to apattern on a master, said apparatus comprising: first, second, and thirdchucks which hold the substrates; a first fine adjustment stage whichholds said first chuck to perform fine driving; a second fine adjustmentstage which holds said second chuck to perform fine driving; a coarseadjustment stage on which said first and second fine adjustment stagesare mounted and which can move in an X Y plane substantiallyperpendicular to an optical axis; an exposure unit which performs anexposure operation for the substrate held by said first chuck; ameasurement unit which performs a measurement operation for thesubstrate held by said second chuck; and a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck, wherein a driving stroke of said second fine adjustment stage isset to be longer than a driving stroke of said first fine adjustmentstage.
 46. The apparatus according to claim 45, further comprising achuck in addition to said first to third chucks.
 47. The apparatusaccording to claim 45, wherein the master and substrates are broughtinto a stationary state during the exposure operation.
 48. The apparatusaccording to claim 45, wherein the master and substrates are scannedduring the exposure operation.
 49. An exposure apparatus which exposessubstrates to a pattern on a master, said apparatus comprising: first,second, and third chucks which hold the substrates; a first fineadjustment stage which holds said first chuck to perform fine driving; asecond fine adjustment stage which holds said second chuck to performfine driving; a coarse adjustment stage on which said first and secondfine adjustment stages are mounted and which can move in an X Y planesubstantially perpendicular to an optical axis; an exposure unit whichperforms an exposure operation for the substrate held by said firstchuck; a measurement unit which performs a measurement operation for thesubstrate held by said second chuck; and a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck, wherein said first and second fine adjustment stages havedifferent mechanical resonance frequencies.
 50. The apparatus accordingto claim 49, further comprising a chuck in addition to said first tothird chucks.
 51. The apparatus according to claim 49, wherein themaster and substrates are brought into a stationary state during theexposure operation.
 52. The apparatus according to claim 49, wherein themaster and substrates are scanned during the exposure operation.
 53. Anexposure apparatus which exposes substrates to a pattern on a master,said apparatus comprising: first, second, and third chucks which holdthe substrates; a first fine adjustment stage which holds said firstchuck to perform fine driving; a second fine adjustment stage whichholds said second chuck to perform fine driving; a coarse adjustmentstage on which said first and second fine adjustment stages are mountedand which can move in an X Y plane substantially perpendicular to anoptical axis; an exposure unit which performs an exposure operation forthe substrate held by said first chuck; a measurement unit whichperforms a measurement operation for the substrate held by said secondchuck; and a controller which drives said coarse adjustment stage andcauses said measurement and exposure units to perform the measurementand exposure operations, respectively, wherein said controller performsin parallel the measurement and exposure operations for the substratesby serially performing: (i) an operation of unloading the substratehaving undergone the exposure operation together with said first chuckfrom said first fine adjustment stage, (ii) an operation of moving thesubstrate having undergone the measurement operation from said secondfine adjustment stage to said first fine adjustment stage while thesubstrate is held by said second chuck, and (iii) an operation ofloading a substrate to be subjected to the measurement operation nextwhile the substrate is held by said third chuck, wherein controlparameters for said first and second fine adjustment stages in anexposure operation by said exposure unit are made to differ from controlparameters for said first and second fine adjustment stages in ameasurement operation, to be performed during the exposure operation,for a position of an alignment mark for a measurement shot on each ofthe substrates by said measurement unit.
 54. The apparatus according toclaim 53, further comprising a chuck in addition to said first to thirdchucks.
 55. The apparatus according to claim 53, wherein the master andsubstrates are brought into a stationary state during the exposureoperation.
 56. The apparatus according to claim 53, wherein the masterand substrates are scanned during the exposure operation.
 57. Anexposure apparatus which exposes substrates to a pattern on a master,said apparatus comprising: first, second, and third chucks which holdthe substrates; a first fine adjustment stage which holds said firstchuck to perform fine driving; a second fine adjustment stage whichholds said second chuck to perform fine driving; a coarse adjustmentstage on which said first and second fine adjustment stages are mountedand which can move in an X Y plane substantially perpendicular to anoptical axis; an exposure unit which performs an exposure operation forthe substrate held by said first chuck; a measurement unit whichperforms a measurement operation for the substrate held by said secondchuck; and a controller which drives said coarse adjustment stage andcauses said measurement and exposure units to perform the measurementand exposure operations, respectively, wherein said controller performsin parallel the measurement and exposure operations for the substratesby serially performing: (i) an operation of unloading the substratehaving undergone the exposure operation together with said first chuckfrom said first fine adjustment stage, (ii) an operation of moving thesubstrate having undergone the measurement operation from said secondfine adjustment stage to said first fine adjustment stage while thesubstrate is held by said second chuck, and (iii) an operation ofloading a substrate to be subjected to the measurement operation nextwhile the substrate is held by said third chuck, wherein a bar mirror isprovided in each of said first and second fine adjustment stages toenable position measurement in X and Y directions by a laserinterferometer of said coarse adjustment stage, and a relative error inthe X direction and a relative error in the Y direction of each barmirror of said first and second fine adjustment stages can be measuredby driving said coarse adjustment stage in the X and Y directions whileat least one of said first and second fine adjustment stages is fixedwith respect to said coarse adjustment stage.
 58. The apparatusaccording to claim 57, further comprising a chuck in addition to saidfirst to third chucks.
 59. The apparatus according to claim 57, whereinthe master and substrates are brought into a stationary state during theexposure operation.
 60. The apparatus according to claim 57, wherein themaster and substrates are scanned during the exposure operation.
 61. Anexposure apparatus which exposes substrates to a pattern on a master,said apparatus comprising: first, second, and third chucks which holdthe substrates; a first fine adjustment stage which holds said firstchuck to perform fine driving; a second fine adjustment stage whichholds said second chuck to perform fine driving; a coarse adjustmentstage on which said first and second fine adjustment stages are mountedand which can move in an X Y plane substantially perpendicular to anoptical axis; an exposure unit which performs an exposure operation forthe substrate held by said first chuck; a measurement unit whichperforms a measurement operation for the substrate held by said secondchuck; and a controller which drives said coarse adjustment stage andcauses said measurement and exposure units to perform the measurementand exposure operations, respectively, wherein said controller performsin parallel the measurement and exposure operations for the substratesby serially performing: (i) an operation of unloading the substratehaving undergone the exposure operation together with said first chuckfrom said first fine adjustment stage, (ii) an operation of moving thesubstrate having undergone the measurement operation from said secondfine adjustment stage to said first fine adjustment stage while thesubstrate is held by said second chuck, and (iii) an operation ofloading a substrate to be subjected to the measurement operation nextwhile the substrate is held by said third chuck, wherein a plurality ofprojections are formed in each of upper surfaces of top plates of saidfirst and second fine adjustment stages.
 62. The apparatus according toclaim 61, further comprising a chuck in addition to said first to thirdchucks.
 63. The apparatus according to claim 61, wherein the master andsubstrates are brought into a stationary state during the exposureoperation.
 64. The apparatus according to claim 61, wherein the masterand substrates are scanned during the exposure operation.
 65. Anexposure apparatus which exposes substrates to a pattern on a master,said apparatus comprising: first, second, and third chucks which holdthe substrates; a first fine adjustment stage which holds said firstchuck to perform fine driving; a second fine adjustment stage whichholds said second chuck to perform fine driving; a coarse adjustmentstage on which said first and second fine adjustment stages are mountedand which can move in an X Y plane substantially perpendicular to anoptical axis; an exposure unit which performs an exposure operation forthe substrate held by said first chuck; a measurement unit whichperforms a measurement operation for the substrate held by said secondchuck; and a controller which drives said coarse adjustment stage andcauses said measurement and exposure units to perform the measurementand exposure operations, respectively, wherein said controller performsin parallel the measurement and exposure operations for the substratesby serially performing: (i) an operation of unloading the substratehaving undergone the exposure operation together with said first chuckfrom said first fine adjustment stage, (ii) an operation of moving thesubstrate having undergone the measurement operation from said secondfine adjustment stage to said first fine adjustment stage while thesubstrate is held by said second chuck, and (iii) an operation ofloading a substrate to be subjected to the measurement operation nextwhile the substrate is held by said third chuck, wherein said coarseadjustment stage is driven at a high speed when said first and secondfine adjustment stages each have a chuck or when said first and secondfine adjustment stages have no chucks.
 66. The apparatus according toclaim 65, further comprising a chuck in addition to said first to thirdchucks.
 67. The apparatus according to claim 65, wherein the master andsubstrates are brought into a stationary state during the exposureoperation.
 68. The apparatus according to claim 65, wherein the masterand substrates are scanned during the exposure operation.
 69. Anexposure apparatus which exposes substrates to a pattern on a master,said apparatus comprising: first, second, and third chucks which holdthe substrates; a first fine adjustment stage which holds said firstchuck to perform fine driving; a second fine adjustment stage whichholds said second chuck to perform fine driving; a coarse adjustmentstage on which said first and second fine adjustment stages are mountedand which can move in an X Y plane substantially perpendicular to anoptical axis; an exposure unit which performs an exposure operation forthe substrate held by said first chuck; a measurement unit whichperforms a measurement operation for the substrate held by said secondchuck; and a controller which drives said coarse adjustment stage andcauses said measurement and exposure units to perform the measurementand exposure operations, respectively, wherein said controller performsin parallel the measurement and exposure operations for the substratesby serially performing: (i) an operation of unloading the substratehaving undergone the exposure operation together with said first chuckfrom said first fine adjustment stage, (ii) an operation of moving thesubstrate having undergone the measurement operation from said secondfine adjustment stage to said first fine adjustment stage while thesubstrate is held by said second chuck, and (iii) an operation ofloading a substrate to be subjected to the measurement operation nextwhile the substrate is held by said third chuck, wherein a chuck is heldon each of said first and second fine adjustment stages, and at leastone chuck is provided outside said coarse adjustment stage in theexposure and measurement operations, and each of the chucks outside saidcoarse adjustment stage performs all or some of unloading of a substratefrom the chuck, loading of a substrate to be processed next, measurementof a height of a chuck reference plane, measurement of a position of achuck reference mark, measurement of a height of the substrate,measurement of a position of an alignment mark on the substrate, andrelative alignment of the alignment mark on the substrate with the chuckreference mark, in parallel with the exposure and measurement operationson said coarse adjustment stage.
 70. The apparatus according to claim69, further comprising a chuck in addition to said first to thirdchucks.
 71. The apparatus according to claim 69, wherein the master andsubstrates are brought into a stationary state during the exposureoperation.
 72. The apparatus according to claim 69, wherein the masterand substrates are scanned during the exposure operation.
 73. Anexposure apparatus which exposes substrates to a pattern on a master,said apparatus comprising: first, second, and third chucks which holdthe substrates; a first fine adjustment stage which holds said firstchuck to perform fine driving; a second fine adjustment stage whichholds said second chuck to perform fine driving; a coarse adjustmentstage on which said first and second fine adjustment stages are mountedand which can move in an X Y plane substantially perpendicular to anoptical axis; an exposure unit which performs an exposure operation forthe substrate held by said first chuck; a measurement unit whichperforms a measurement operation for the substrate held by said secondchuck; and a controller which drives said coarse adjustment stage andcauses said measurement and exposure units to perform the measurementand exposure operations, respectively, wherein said controller performsin parallel the measurement and exposure operations for the substratesby serially performing: (i) an operation of unloading the substratehaving undergone the exposure operation together with said first chuckfrom said first fine adjustment stage, (ii) an operation of moving thesubstrate having undergone the measurement operation from said secondfine adjustment stage to said first fine adjustment stage while thesubstrate is held by said second chuck, and (iii) an operation ofloading a substrate to be subjected to the measurement operation nextwhile the substrate is held by said third chuck, wherein said chuckscirculate and move through a clean air space, a nitrogen purged space,or a vacuum space, a substrate having undergone exposure is detachedfrom the corresponding chuck at an unloading position of the space andis unloaded from the space to an outer air side, and a substrate to beexposed is loaded at a loading position of the space from the outer airside to the corresponding chuck.
 74. The apparatus according to claim73, wherein both unloading of a substrate from a chuck in the clean airspace, nitrogen purged space, and vacuum space, and unloading of a chuckfrom the space, are performed by the same unloading unit.
 75. Theapparatus according to claim 73, further comprising a chuck in additionto said first to third chucks.
 76. The apparatus according to claim 73,wherein the master and substrates are brought into a stationary stateduring the exposure operation.
 77. The apparatus according to claim 73,wherein the master and substrates are scanned during the exposureoperation.
 78. An exposure apparatus which exposes substrates to apattern on a master, said apparatus comprising: first, second, and thirdchucks which hold the substrates; a first fine adjustment stage whichholds said first chuck to perform fine driving; a second fine adjustmentstage which holds said second chuck to perform fine driving; a coarseadjustment stage on which said first and second fine adjustment stagesare mounted and which can move in an X Y plane substantiallyperpendicular to an optical axis; an exposure unit which performs anexposure operation for the substrate held by said first chuck; ameasurement unit which performs a measurement operation for thesubstrate held by said second chuck; and a controller which drives saidcoarse adjustment stage and causes said measurement and exposure unitsto perform the measurement and exposure operations, respectively,wherein said controller performs in parallel the measurement andexposure operations for the substrates by serially performing: (i) anoperation of unloading the substrate having undergone the exposureoperation together with said first chuck from said first fine adjustmentstage, (ii) an operation of moving the substrate having undergone themeasurement operation from said second fine adjustment stage to saidfirst fine adjustment stage while the substrate is held by said secondchuck, and (iii) an operation of loading a substrate to be subjected tothe measurement operation next while the substrate is held by said thirdchuck, wherein a position of a chuck reference mark is measured againafter the exposure operation in said exposure unit or the measurementoperation in said measurement unit, and cleaning of top plates of saidfine adjustment stages, issuance of a warning, or an abnormal stop isperformed when a measurement result exceeds a predetermined amount. 79.The apparatus according to claim 78, further comprising a chuck inaddition to said first to third chucks.
 80. The apparatus according toclaim 78, wherein the master and substrates are brought into astationary state during the exposure operation.
 81. The apparatusaccording to claim 78, wherein the master and substrates are scannedduring the exposure operation.
 82. An exposure apparatus which exposessubstrates to a pattern on a master through a projection system, saidapparatus comprising: first, second, and third chucks which hold thesubstrates, wherein said first chuck also serves as said third chuck; afine adjustment stage which holds said first chuck to perform finedriving; a chuck holding unit which holds said second chuck; a coarseadjustment stage on which said fine adjustment stage and chuck holdingunit are mounted and which can move in an X Y plane substantiallyperpendicular to an optical axis of the projection system; an exposureunit which performs an exposure operation for the substrate held by saidfirst chuck; a measurement unit which performs a measurement operationfor the substrate held by said second chuck; and a controller whichdrives said coarse adjustment stage and causes said measurement andexposure units to perform the measurement and exposure operations,respectively, wherein said controller performs in parallel themeasurement and exposure operations for the substrates by seriallyperforming: (i) an operation of unloading the substrate having undergonethe exposure operation together with said first chuck from said fineadjustment stage, (ii) an operation of moving the substrate havingundergone the measurement operation from said chuck holding unit to saidfine adjustment stage while the substrate is held by said second chuck,and (iii) an operation of loading the substrate to be subjected to themeasurement operation next to said chuck holding unit while thesubstrate is held by said third chuck.
 83. The apparatus according toclaim 82, further comprising a chuck in addition to said first to thirdchucks.